Journal of the College of Optometrists in Vision Development

ISSN 2374-6416 • Volume 1, Issue 1

TABLE OF CONTENTS Editorial Ida Chung, OD, MSHE, FAAO, FCOVD Welcome to Vision Development and Rehabilitation ...... 4

Leonard J. Press, OD, FAAO, FCOVD Editorial: A New Beginning ...... 5

Dominick M. Maino, OD, MEd, FAAO, FCOVD-A Guest Editorial: Agenda Driven Research ...... 7

Perspective Bruce Bridgeman, PhD, Susan R. Barry, PhD Survey of Patients with Stereopsis Acquired as Adults . . . . . 13

Feature Naveen K. Yadav, BS (Optom), MS, PhD, Kenneth J. Ciuffreda, OD, PhD, Kevin T. Willeford, OD, MS, Preethi Thiagarajan, BS (Optom), MS, PhD, and Diana P. Ludlam, BS, COVT VEP and Human Attention: Translation from Laboratory to Clinic ...... 14

Articles Naveen K. Yadav, BS (Optom), MS, PhD, and Kenneth J. Ciuffreda OD, PhD Assessing Hemianopia Objectively in Stroke Patients Using the VEP Technique: A Pilot Study ...... 30

Thomas Kollodge, BS, Sarah Hinkley, OD, FCOVD Retinoblastoma; a Scientific and Clinical Review ...... 39

Paul Lederer, OD, Dmitri Poltavski, PhD, David Biberdorf, OD Confusion inside Panum’s Area and Symptomatic Convergence Insufficiency ...... 46

44th Annual Meeting Oral Papers and Posters ...... 61

1 Journal of the College of Optometrists in Vision Development ISSN 2374-6416 • Volume 1, Issue 1

Vision Development & Rehabilitation College of Optometrists in Editorial Staff Vision Development Board of Directors Editor-in-Chief President Leonard J. Press, OD, FAAO, FCOVD Ida Chung, OD, MHSE, FAAO, FCOVD Managing Editor President-Elect Katie Kirschner, MS Kara Heying, OD, FCOVD Advertising Manager Vice President Jackie Cencer, CMP Christine Allison, OD, FCOVD Graphic Design & Production Secretary-Treasurer Averill & Associates Creative Lab, Inc. Barry Tannen, OD, FCOVD Mary B. Averill, President Immediate Past President David Damari, OD, FCOVD

SUBMISSION OF MANUSCRIPTS Directors The entire manuscript submission and review process is conducted Marie Bodack, OD, FCOVD through Editorial Manager. All manuscripts are submitted at Jennifer Dattolo, OD, FCOVD www.editorialmanager.com/vdr. A copy of Guidelines for Authors is available on the home page of the VDR Editorial Pat Pirotte, OD, FCOVD Manager site or on the COVD website http://www.covd. org/?page=VDR. Editorial Manager will require you, as an Author Daniel Press, OD, FCOVD and/or Reviewer, to create an account the first time you access the site. If you have questions with the site or the process please Executive Director contact Managing Editor, Katie Kirschner at [email protected]. Pamela R. Happ, MSM, CAE If access to Editorial Manager is not available please e-mail the Editor with your request for the Guidelines and submit your Vision Development & Rehabilitation (VDR) is published manuscripts to [email protected]. quarterly by the College of Optometrists in Vision Development. All rights reserved. No part of this publication may be reproduced or utilized in any form without permission in writing from the Editor. ISSN 2374-6416. All expressions of opinions Beta Sigma Kappa Application Guidelines . . . .12 and statements of supposed fact published in signed articles Thanks to Our Sponsors for do not necessarily reflect the views or policies of the College the COVD 45th Annual Meeting ...... 38 of Optometrists in Vision Development (COVD), which does not endorse any specific educational program or products advertised Are You Connected? ...... 45 in VDR. Letters to the Editor may be edited for content Thanks to the Exhibitors for Their Support of and space availability. Acceptance of advertising or optical industry news for publication in VDR does not imply approval our COVD 45th Annual Meeting ...... 60 or endorsement of any product or service by either VDR or COVD PSAs Available in High Definition . . . . .91 COVD. Editorial Office: Journal correspondence regarding manuscripts, letters, and reports should be addressed to: Editor- 46th Annual Meeting ...... 93 in-Chief, Leonard Press, OD, FCOVD, and send to editor@covd. Event Calendar ...... 94 org. Please contact the editor for a copy of the VDR Guidelines for Authors or download at http://www.covd.org/?page=VDR. Production: Averill & Associates Creative Lab, Inc., 17654 Walnut Thank You to our Advertisers: Trail, Chagrin Falls, OH 44023. Any article, editorial, column or other item submitted to the VDR by an author for review Bernell Expansion Consultants NuSquared and eventual publication indicates the authors’ approval for publication and assignment of copyright to VDR. VDR is indexed in the Directory of Open Access Journals.

2 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Journal of the College of Optometrists in Vision Development ISSN 2374-6416 • Volume 1, Issue 1

Journal Review Board

Curtis Baxstrom, OD, FCOVD, FNORA Mark Mintz, MD Chris Chase, PhD, FAAO G. Lynn Mitchell, MAS, FAAO Kenneth Ciuffreda, OD, PhD, FCOVD-A Maureen Powers, PhD, FCOVD-A Michael Gallaway, OD, FAAO, FCOVD Beth Rolland, OTR, CDRS Sarah Hinkley, OD, FAAO, FCOVD Jack Richman, OD, FAAO, FCOVD Neera Kapoor, OD, MS, FAAO, FCOVD-A Mitchell Scheiman, OD, FAAO, FCOVD Diana Ludlam, COVT Samantha Slotnick, OD, FAAO, FCOVD W.C. Maples, OD, MS, FAAO, FACBO, FCOVD Barry Tannen, OD, FAAO, FCOVD

Editor’s Advisory Board

Paul Freeman, OD, FAAO, FCOVD Former Editor of Optometry

Dominick Maino, OD, MEd, FAAO, FCOVD-A Former Editor of Optometry and Vision Development

Irwin Suchoff, OD, DOS Former Editor of Journal of Behavioral Optometry

Marc Taub, OD, FAAO, FCOVD Current Editor of Optometry and Visual Performance

3 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Editorial: Welcome to Vision Development and Rehabilitation Ida Chung, OD, MHSE, FAAO, FCOVD

The College of Optometrists in Vision Development is extremely pleased to present to our readers Vision Development and Rehabilitation (VDR), for this journal advances the mission of COVD — improving lives by advancing excellence in optometric vision therapy through education and board certification. VDR also exemplifies the vision of COVD — To facilitate ongoing progress in developmental vision care, advocate for “Dr . Press is a close friend and colleague wider adoption of optometric vision therapy, whom I have known since I was a student and increase recognition of its integral role in at the Pennsylvania College of Optometry enhancing learning, rehabilitation, productivity, and he was the Chief of the Binocular and overall quality of life. As such, VDR Vision Clinic . I knew he was the perfect embodies the advancement of developmental person to become the Founding Editor of vision care, vision therapy and vision rehabili­ “Vision Development and Rehabilitation,” tation to improve patient’s quality of life but I had some trepidation in asking him through a better understanding of vision and to take on such a large commitment . multi-sensory rehabilitation. After due thought and consideration, he The COVD board wishes to recognize the answered in the affirmative and I knew many people whose unwavering enthusiasm, that our journal was off to a great start ”. persistence, and support made this first issue of VDR a reality. These individuals include — Barry Tannen, OD, FCOVD our friend and colleague Dr. Leonard J. Press and his editorial review board, and the COVD international office. “I am so excited to have a new journal Thank you for reading the first issue of highlighting this area of Optometry . I look Vision Development and Rehabilitation, with forward to it as an academic because the promise of many more issues to come. it will give me more options of places to

publish . As a reader, I am excited to read about more interesting cases from which I can learn new management strategies to help my patients . I can’t wait to read this first issue!”

— Christine Allison, OD, FCOVD

4 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Editorial: A New Beginning Leonard J. Press, OD, FAAO, FCOVD, Editor-in-Chief

It is my distinct pleasure to introduce our new journal, Vision Development and Rehabilitation (VDR), the official journal of the College of Optometrists in Vision Development. Before addressing the contents of the journal, I’d like to share a little bit of history with you. The quarterly journal known as the Journal of Optometric Vision cognitive rehabilitation, behavioral vision Development was introduced in 1975. Its first care, visual impairment, applied cognitive editor was Dr. Robert Wold, who seeded many and visual neuroscience, behavioral medicine, beginnings in our organization, followed one occu­pa­tional and physical therapy, learning year later by Dr. Martin Kane and subsequently and education. Reviews, case reports, and by Drs. James Bosse, Sidney Groffman, and perspective pieces will be considered, but Dominick Maino. priority will be accorded to manuscripts Each editor has had an impact on the of original research. Appealing to a trans- evolution of the Journal. These distinctions disciplinary view of vision, the journal’s have been transformative, and served review board is comprised of professionals as a bridge to where we are today. Dr. from the disciplines of Optometry, Vision Kane incorporated ERIC abstracts and an Science, Medicine, Occupational Therapy, and Annual Review of the Literature. Dr. Bosse Biostatistics. commissioned Annual Topical Subject Reviews, This inaugural issue leads with a Guest and I had the privilege of writing a number Editorial on Agenda Driven Research from Dr. of them. Dr. Groffman added thought- Dominick Maino, which is thought provoking provoking editorials and a wide-ranging style. in a constructive way. You’ll see what I mean Dr. Maino engineered the online presence of when you read it, and our intent in publishing the journal and a name change to Optometry it is to catalyze further dialogue in the clinical, and Vision Development . For a period of one didactic and research communities. year in 2013, COVD and OEPF combined their A unique opportunity for crowd sourcing respective journals into Optometry and Vision will occur through the Perspective Piece on Development of which Drs. Maino and Taub Stereoscopic Vision from Drs. Bruce Bridgeman were co-editors. and Susan Barry. Sue is well known to of Vision Development & Rehabilitation is a our readership through prior authorship and quarterly journal featuring scientific, peer- presentations, so permit me to introduce you to reviewed articles in the fields of vision Bruce with whom you may not be as familiar. development and vision rehabilitation. Our Dr. Bridgeman holds a PhD in physiological mission is to serve as an authoritative source psychology from Stanford and is a Professor of of information in vision development and Psychology and Psychobiology at U.C. Santa rehabilitation through peer reviewed articles. Cruz. He is an individual with strabismus who The editor and journal review board will has collaborated with U.C. Berkeley College consider manuscripts in fields related to of Optometry and published an article in the development and rehabilitation, including Academy journal last year about his stereo­scopic but not limited to: optometric vision therapy, experiences after watching the movie Hugo. 5 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 The survey that he and Sue have designed Rehabilitation Association). Although COVD has a weblink so that it can be completed and does not have a formal relationship with NORA, analyzed online. You can be instrumental in the link between vision development in COVD encouraging patients who have developed and vision rehabilitation in NORA sets the stereoscopic vision to complete the survey. stage for a natural synergy in pooled scholarly Our featured paper is VEP and Human activities. Attention: Translation from Laboratory to Clinic, I plan to maintain close ties with the AOA by Yadav, Ciuffreda, Willeford, Thiagarajan, (the American Optometric Association), the and Ludlam, which I believe is destined to AAO (American Academy of Optometry) and become a classic in the field. Ciuffreda and OEPF (the Optometric Extension Program colleagues at SUNY College of Optometry Foundation) and to lend voice to other have consistently been at the cutting edge of organizations with whom you may not be as research in our field. There is a second paper familiar. Our journal will pursue being listed from Yadav and Ciuffreda that is a pilot study, in indices such as PMC (PubMed Central) to in which hemianopia is assessed objectively complement our trans-disciplinary vision. PMC in stroke patients using the VEP Technique. is a full-text archive of biomedical and life Thomas Kollodge and Dr. Sarah Hinkley have sciences journal literature at NIH/NLM, the U.S. contributed a review article on Retinoblastoma. National Institutes of Health’s National Library Dr. Hinkley is a Professor and Chief of Vision of Medicine. As your editor-in-chief, I will tap Rehabilitation Services at Michigan College of into the wisdom of former and current journal Optometry. Rounding out our original papers editors, rely on input from our journal review is the article by Lederer, Poltavsi, and Biberdorf board and reviewers, and welcome feedback looking at nearpoint fixation disparity in the from you - our members and readership. context of convergence insufficiency. Many individuals have been instrumental in In this issue you will also find abstracts of creating VDR, but one who stands out is Ms. papers and posters presented at last year’s Katie Kirschner, our Managing Editor. My thanks Annual Meeting of the College of Optometrists and appreciation is extended to the COVD board in Vision Development. This will be an annual and staff for their support in this endeavor as feature of our journal. I will be attending other we look forward to our journal as an innovative, meetings such as NORA (Neuro-Optometric informative, and educational venture.

6 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Guest Editorial: Agenda Driven Research Dominick M. Maino, OD, MEd, FAAO, FCOVD-A Professor of Pediatrics/Binocular Vision Illinois College of Optometry; Lyons Family Eye Care, Chicago, Illinois

Last summer I was present at a meeting hosted by the School of Optometry at the University of Waterloo. This meeting was attended by the best and the brightest of Europe’s researchers with expertise in pediatric eye problems, amblyopia, strabismus, and issues adversely affecting vision development. I decided to attend the Child Vision Research Society’s meeting for a number of reasons including the outstanding keynote altered and/or changed to make it more speakers. Another reason I wanted to attend meaningful and robust. None of the meetings was that one of the attendees was an individual I usually go to allow uncompleted research to that I had collaborated with on a project whom be presented and do not often have this friendly I had never met in person. She was delightful critique assistance for the researcher. I found this to work with and was also a very well-known an excellent way to introduce new researchers and respected researcher. Researchers, faculty, into the peer research relationship that allows clinicians, and orthoptists from New Zealand, a much gentler approach then what I’ve Nepal, Korea, Israel, the UK and the USA were in experienced in the past. attendance. During the meeting a paper entitled “Does Besides the great keynote speakers (Drs. – And How Does – Vision Therapy (Orthoptic Susan Cotter, Professor, Southern California Treatment) Work?” was then presented. No College of Optometry; Daphne Maurer, constructive criticism was offered even though Professor, Department of Psychology, McMaster there were some serious flaws in the research University; Saint-Amour, Associate Professor, design and interpretation of the outcomes. Department of Psychology at the Université The conclusion of this research was “While du Québec a Montréal), this exceptional vergence exercises have some effect, effort and program featured various paper and poster possibly voluntary influences are a major factor presentations. The final day we were all bussed in effecting change … Very careful attention to The Hospital for Sick Children in Toronto for should be paid to these effects when studying additional lectures and tours of the facility. eye exercises.” The impression given and I soon realized that this particular meeting actually stated was that “eye exercises” did not was somewhat different than those I usually cause the improvement and all the subject had attend. For instance, I noticed that several to do was to “try harder” . of the research projects did not appear to be At noon the group broke for lunch and I completed but rather ongoing in nature. deliberately sought out the presenter. She was a When one of these not quite completed dedicated, excellent researcher. She had a sharp research papers was presented to the 100+ mind and congenial demeanor. I did not discuss member audience, something rare occurred. The my concerns about her research over lunch. I audience, in a non-critical, helpful, “let me be wanted to use that time primarily to get to know your friendly advisor” way offered constructive her in a friendly non-antagonistic environment. criticism on how the project could be improved, Since this presentation was made to a small

7 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 group, during a single meeting, I figured this was years to be effective. I have not not a fight worth fighting at this time. heard from our medical and scientific I was wrong. colleagues that this a major burden for Several months later, the article “Change in their patients when these therapists help convergence and accommodation after two their patients, it appears that only vision weeks of eye exercises in typical young therapy is judged in this manner. adults” by Horwood, Tor, and Riddle appeared 3) The researchers failed to include a single digitally as a Major Article in press for the individual (unlike the CITT study) that had Journal of the American Academy of Pediatric the training, knowledge and perhaps an Ophthalmology and Strabismus.1 It was obvious opposing viewpoint promoted by this to me that the peer review system of AAPOS agenda driven article. If all researchers either broke down or was a willing partner start with the same assumptions, in this agenda driven research publication. biases and predispositions; what is the This was not the first time I had seen what possibility that the research conclusions appears to be a deliberate misuse of the peer would be something other than a review system resulting in the publication of reflection of these assumptions, biases an article with significant problems and/or and predispositions? questionable conclusions.2 [I addressed many of these problems in an editorial that is available Tavris and Aronson, in their text, online of your review (Ophthalmology Causes Mistakes were made, but not by Me: Myopia!) 3. http://goo.gl/n0RONA] Why we justify foolish beliefs, bad decisions and hurtful acts, nicely Specific Problems with the Paper reviews why we find it so difficult to To the authors’ credit they did list several admit when we are wrong. Unfor­ areas of concern that could have affected tunately, even when the facts are the outcomes and conclusions of this article. presented,­ we choose to ignore However they did not point out many of the them and hold on to these erroneous most important shortcomings of this particular beliefs.4 We do not respond well to publication. These areas are discussed below: cognitive dissonance and often use any available mechanism to resolve 1) Poor or a total absence of under­stand­ing this intellectual conflict in a way that what optometric vision therapy is and/or preserves the status quo.5 does. Terms used such as eye exercises 4) The researchers stated in their introduction and the use of quotations around the that the “Research [CITT] concentrated on phrase vision therapy, clearly demonstrate relief of symptoms … without changes to this lack of knowledge and experience the ocular responses…”. This, of course, is and the disdain the researchers have for incorrect. The CITT study not only showed this form of intervention. an improvement in symptoms (as a 2) They single out optometric vision therapy primary outcome) but also in the measures as too time consuming and intensive. of vergence, accommodation and other This shows a lack of understanding areas (a stated secondary outcome) with of the concept of therapy. Physical in office vision therapy with home vision therapy, occupational therapy, speech therapy being the most efficacious. and language therapy and psychological 5) The methods used in this study, have therapeutic intervention often require no, to little relationship to the actual weeks, months and in some situations, procedures utilized by optometrists while

8 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 conducting vision therapy, nor to those tive facility (they did note that they methods used in the CITT clinical trials. used +/-2.00 D); binocular vergence/ a. The subjects in this study were self- accommodation activities (they do not reported asymptomatic college stu­ state if there were any suppression dents, 18-25 years of age. The CITT controls) and placebo therapy subjects were symptomatic and were (“Snakes” illusion, Necker cube, shown clearly to have convergence yoked prisms). No rational was given insufficiency using a mutually agreed for using these placebo therapies. upon set of criteria. The CITT study Unlike the CITT clinical trials, no utilized a research supported survey to research was conducted to show determine if symptoms were present. that these placebo therapies were This study depended upon subjects appropriate to use. who considered themselves to have f. The researchers depended upon the “normal” eyes. honesty of their subjects to report b. The CITT study used those diagnostic missed therapy sessions. They also and therapeutic tools frequently used cell phone alarms and diaries utilized in clinical practice. This study which were “informally” examined used Gabor images and other tools to determine if therapy was done. usually not utilized when conducting Anytime you are conducting therapy at diagnostic testing or a program of home as part of a research study, you therapy. must have an appropriate mechanism c. They stated that “Instructions [to to determine if therapy was actually the subjects] were minimal…”. The conducted or not. The CITT study clinician usually gives fairly detailed had such protocols. This study was instructions so that the patient knows obviously lacking in this area. exactly what to do and how to perform g. One of the most significant and the therapy. Did these subjects have an major flaws of this study was the appropriate understanding of the tasks total lack of understanding of therapy and how to respond? and how it is conducted in the real d. The 156 subjects were divided into 2 clinical world. They used the phrase control groups or to one of six “eye “try harder” with only one group exercise” groups. The second control of subjects and then were surprised group was just asked to “try harder” that that group had such good at performing the task. This resulted in results. In the real world of therapy, 8 experimental groups among 156 test encouragement, asking the patient subjects resulting in a study with a very to try harder, and other mechanisms small number of individuals assigned to that improve outcomes and to achieve each of the experimental groups. success are always utilized. e. There was no description of any of h. Finally, as noted initially, but worth the home “eye exercises”. Depending repeating, these subjects were asymp­ upon the experimental group, the to­matic, apparently had no binocular subjects were asked to do the exercise vision problems and did not require 3 times/day for 5 minutes each time. any therapy whatsoever. The home therapy included monocular push-ups, monocular “jump accom­ One of the statements they made and one mo­dation”, monocular accom­mo­da­ I cannot disagree with was “It is clear that the

9 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 greatest influence in changing responses to an binocular vision problem and not just a problem approaching target is how the participant is of visual acuity and used binocular vision instructed and the amount of effort exerted.” therapy to treat this dysfunction. We have Functional optometrists and their therapists use always known that the research of Hubel and a well-crafted instruction set when conducting Wiesel was inappropriately interpreted and that diagnostic and therapeutic activities and like this resulted in delayed or no treatment for tens all therapists always encourage the very best of thousands of patients. efforts from their patients. Research supports the ability to treat One of the statements at the very end of the amblyopia at any age.b Research supports paper that has little to no scientific support or that treating amblyopia as a binocular justification was “In the view of the importance vision problem using binocular therapy is of effort in comparison to true treatment appropriate.8,9,10,11 effects of different exercises and the costs Ophthalmology and those who supported in terms of professional time, loss schooling, ophthalmology should have known this as well. and many office visits of a long course of in- They should have known this since those adult office vision therapy, maximizing motivation patients who were amblyopic and then lost and feedback strate­­gies or less costly home vision in the better seeing eye, almost always exercises seems desirable.” Is it really less costly had an improved visual acuity in the amblyopic to recommend a home therapy procedure, eye over time. They chose to ignore what they when the CITT studies clearly showed in-office were seeing clinically, in large part, because it therapy was the most efficacious? Out of office did not fit their beliefs and biases and because therapy often involves multiple trips to the it supported the views of functional optometry. office for progress evaluations and in the end a We were right about refractive error. The recommendation for in-office therapy in most environment does influence its development instances. and that if that environment is manipulated This paper failed on many different levels appropriately, you can alter refractive error when trying to answer the question, “Does outcomes.12,13,14 – And How Does – Vision Therapy (Orthoptic We were right about learning related vision Treatment) Work?” If they had reviewed problems. Well, this one has support on both Ciuffreda’s 2002 paper (The scientific basis for sides of the issue. The CITT-ART study15 should and efficacy of Optometric vision therapy in help resolve some of the questions regarding nonstrabismic accommodative and vergence vision therapy and how it affects academic disorders)6 they would have had a better performancec,d. understanding of the science supporting vision The more complex reason has to do with therapy. agenda driven research and the mechanisms Why did this paper appear in print? The involved when these papers are presented and answer is perhaps both simple and complex. published. Agenda driven research does not Medicine, various researchers and others may promote good science. It does not promote fear that functional optometry has been right honest inquiry and it does not support better all along. patient care. Functional optometry was right about It is time for all to put aside our agendas, amblyopia.a We have always supported the our biases, our preconceived notions. It is time concept that neuroplasticity is present at all to work together to determine best practices ages.7 We have always known clinically that even if it is contrary to prevailing opinion. The amblyopia could be treated at any age. We world is not flat. Amblyopia can be treated at have always known that amblyopia was a any age. And optometric vison therapy is an

10 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 appropriate treatment modality for disorders of 6. Ciuffreda KJ. The scientific basis for and efficacy of optometric vision therapy in nonstrabismic accommodative he binocular vision system. and vergence disorders. Optometry. 2002;73(12):735-62. 7. Maino D, Donati, R, Pang, Viola S, Barry S. Neuroplasticity. Footnotes In Taub M, Bartuccio M, Maino D. (Eds) Visual Diagnosis and Care of the Patient with Special Needs; Lippincott a. For a review of many of the PEDIG study see this Slideshare Williams & Wilkins. New York, NY;2012:275-288. presentation: http://goo.gl/3WjN4p 8. Levi DW, Li RW. Perceptual learning as a potential b. For a review of articles dealing with vision and learning treatment­ for amblyopia: A mini-review. Vis Research see: http://goo.gl/aZcY8S 2009;49(21): 2535–2549 c. Joint Statement on Vision, Learning and Dyslexia: http:// 9. Bavelier D, Levi DW, Li RW et al. Removing brakes on goo.gl/izyROZ adult brain plasticity: from molecular to behavioral d. Care of the Patient with Learning Related Vision Problems: interventions. J Neuroscience 2010 30(45):14964-14971 http://goo.gl/gfuvpP 10. Li RW, Ngo C, Nguyen J, Levi DM. Video-game play induces plasticity in the visual system of adults with amblyopia. 2011;PLoS Biol 9(8): e1001135. doi: 10.1371/journal. References pbio.1001135. available from http://goo.gl/ewpyuQ 1. Horwood AM, Tor SS, Riddle PM. Change in convergence accessed 1/2015 and accommodation after two weeks of eye exercises 11. Astle AT, Webb BS, McGraw PV. Can perceptual learning be in typical youg adults. Journal of the Amer Acad Pediat used to treat amblyopia beyond the critical period of visual Ophthal Strab. 2014;1-7. development? Ophthalmic Physiol Opt 2011;31:564-573. 2. Donahue S. How often are spectacles prescribed to 12. Sankaridurg P, Holden B, Smith E, et al. Decrease in rate “normal” preschool children? JAAPOS; 2004: 8(3):224– of myopia progression with a contact lens designed to 229. (available from http://goo.gl/zRJEn3) reduce relative peripheral hyperopia: one-year results. 3. Maino D. Ophthalmology Causes Myopia! J Optom Vis Invest. Ophthalmol. Vis. Sci. 2011;52(13): 9362-9367. Dev 2004;35 (2):67-69. 13. Cheng D, Woo GC, Schmid KL. Bifocal lens control of 4. Maino D. Mistakes were made (Yes by you!). Optom Vis myopic progression in children. Clin Experimental Optom Dev 2011;42(2):66-69 2011; 94(1):24–32 5. Maino D. An Open Letter to David K Wallace, MD, MPH 14. Rose KA, Morgan IG, Ip J. Outdoor activity reduces the (and other disbelievers and holders of outdated and biased prevalence of myopia in children. Ophthalmology 2008; opinions and beliefs). Optom Vis Dev 2008;39(4):178- 115(8):1279–1285 180. 15. CITT-ART information: http://citt-art.com/

11 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Beta Sigma Kappa — COVD Research Grant Application Guidelines Background • Institution and other resources available The Beta Sigma Kappa (BSK) – COVD Research • Relevance of problem to clinical optometry, Grant program administered by the College of vision science, or eye related public health Optometrists in Vision Development (COVD) supports • Plans for publication optometric and vision science faculty research and • Time table optometric resident research. The fund will provide c. Budget explanation support for optometric faculty research and/or • State amount of grant request optometric resident research in binocular vision and/ • Describe/Itemize costs or visual performance issues. Annual grant will consist • Justification for equipment, supplies and up to $2,000. other expenses

Award and Eligibility Note: Nominal research subject payments are allowable. All optometric related faculty and optometry d. Helsinki declaration (required only if human residents at an accredited school or college of subjects involved) optometry, irrespective of membership in BSK or COVD, are eligible to apply for a BSK-COVD Research e. Letter of endorsement by faculty advisor, Dean Grant. or President/Director of the school/college that One grant will be awarded up to $2,000 annually. also indicates the proposal was reviewed and Funds support research conducted for a period up to meets with the standards of the institution. one year. Both BSK and COVD are 501(c)(3) non-profit Submissions and supporting materials should be organiza­tions; our policy is not to cover any indirect emailed to [email protected] and include the words costs associated with research grants for any other BSK + last name of applicant in the subject line of the of our programs. This policy applies uniformly to all email. award recipients. Submissions will receive a confirmation receipt by Recipients must submit a final report of their e-mail from COVD within 3 business days of receipt. research findings no later than one year post award If you do not receive a confirmation, contact Jackie or the applicant and/or institution become ineligible Cencer at [email protected] or 330.995.0718 office for funding the subsequent year. The preferred to ensure the application is on file. submission is an article in a form suitable for Submissions will be reviewed by the BSK Board of publication. Regents and the BSK Central World Council, both in Recipients are encouraged to present at collaboration with the COVD. the annual meeting of COVD and to submit a manuscript to an optometric journal for publication. Recognition of Awardees Any manuscript or publication material produced The award recipient(s) and an institution must acknowledge­ Beta Sigma Kappa International representative­­ will be invited to attend the COVD Optometric Honor Society and the College of Annual Meeting where at the COVD Awards Optometrists in Vision Development. Luncheon, the recipient(s) will be recognized. All award recipients by application and Deadline acceptance of an award agree to allow the COVD The deadline for applications is August 1st. and the program sponsor, Beta Sigma Kappa Submission and Review Procedures International Honor Society, to publish their name, Submissions should consist of 6 pages or less, image, institution information, and any statement or preferably in PDF format and contain the following: quote provided by the recipient. These may appear a. Cover page with project title, institution and in a variety of media formats that will announce and address, name (including degree(s)), and title promote the program including, but not limited to, for faculty member with contact information. the COVD and/or sponsor annual report, website, b. Research plan social media, newsletters, and annual meeting • Statement of problem promotional materials. • Experimental design For additional information about this award and the College of Optometrists in Vision Development, contact Jackie Cencer, at [email protected] or 330.995.0718.

12 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Perspective: Survey of Patients with Stereopsis Acquired as Adults Bruce Bridgeman, PhD University of California, Santa Cruz Susan R. Barry, PhD Mt . Holyoke College In recent years it has become clear that those born with deficient stereoscopic vision can acquire this capacity as adults under some circumstances. Sue Barry, who had no measurable stereopsis, acquired better than 100 arcseconds of stereoacuity following one year of optometric vision therapy (Barry, 2009). Bruce Bridgeman experienced stereopsis after viewing the film “Hugo” in 3D (Bridgeman, 2014), an ability that has endured for more than two years. Fortunately, professionally measured stereoscopic thresholds were available for periods both before and after the Hugo experience; static stereoacuity improved from 200 arc seconds on Wirt Circles before the experience to 80 are seconds afterward. Media the experiences of those who had acquired reports on CNN, BBC and other sources resulted stereopsis. in emails from people all over the world who To extend this survey to the maximum num- had similar experiences. ber of patients, we are asking optometrists and This raises the possibility that some patients other vision professionals to offer the survey to viewing a 2-hour film in stereoscopic 3D might patients who have acquired stereopsis, either experience benefits such as those gained through formal training or informal experience through more formalized therapy. For future such as viewing a 3D film.The survey is avail- clinical interventions it is important to know able online at http://bit.ly/1vThYaM. for the recovered patients both what kinds of References visual anomalies resulted in poor stereopsis, and 1. Barry, S. R. Fixing My Gaze: A Scientist’s Journey into Seeing what kinds of experiences triggered acquisition in Three Dimensions. New York, NY: Basic Books; 2009. of stereopsis. To investigate this further, 2. Bridgeman, B. Restoring adult stereopsis: A vision researcher’s Bridgeman has created a survey to document personal experience. Optom Vis Sci 2014;91(6):135-139

13 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Featured Article: VEP and Human Attention: Translation from Laboratory to Clinic Naveen K. Yadav, B.S. (Optom), MS, PhD Kenneth J. Ciuffreda, OD, PhD Kevin T. Willeford, OD, MS Preethi Thiagarajan, B.S. (Optom), MS, PhD Diana P. Ludlam, BS, COVT SUNY State College of Optometry, Department of Biological and Vision Sciences

abstract The purpose is to review recent studies from our laboratory that used the visual-evoked potential (VEP) to assess attention in both the visually-normal (VN) and mild traumatic brain injury (mTBI) populations. The VEP (amplitude and latency), and attention-related alpha band responses, were assessed. The alpha responses were abnormal in those with mTBI. Furthermore, these values differentiated well between mTBI with versus without an attentional deficit. Following oculomotor vision rehabilitation, the alpha and VEP responses increased significantly. The VEP technique can be used reliably in both clinic and laboratory settings to detect attention objectively in both VN and mTBI populations.

Introduction traumatic brain injury (mTBI), the most common Traumatic brain injury (TBI) is a major health variety of TBI (~70-80%), occurs as a result of issue in the United States.1 Approx­imately 1.7 injury to the brain due to blunt or penetrating million people suffer from a TBI annually. Mild head insult.2 It produces widespread damage to the underlying brain tissues. This occurs due to the initial and immediate biomechanical effects3 Correspondence regarding this article should be emailed to Naveen K . Yadav at [email protected] or call (e.g., coup-countrecoup, shearing, etc.), as 212-938-5774. All statements­ are the author’s personal well as the subsequent adverse biomolecular/ opinion and may not reflect the opinions of the College of biochemical changes that occur over the next Optometrists in Vision Development, Vision Development days and weeks.4,5 These effects produce diffuse & Rehabilitation or any institution or organization to which the author may be affiliated . Permission to use axonal injury (DAI). The DAI is responsible for reprints of this article must be obtained from the editor . slowing and delaying cortical information Copyright 2015 College of Optometrists in Vision processing.6 Development . VDR is indexed in the Directory of Open mTBI results in a constellation of adverse Access Journals . Online access is available at covd.org . https://doi.org/10.31707/VDR2015.1.1.p14 effects. These are of a sensory, motor, perceptual, ling­uistic, cognitive, attentional, and/or behavioral 7-9 Yadav N, Ciuffreda K, Willeford K, Thiagarajan P, Ludlam, nature. Most of the cranial nerves (i.e., II, III, D. Vep and human attention: translation from laboratory IV, V, VI, VII, VIII, and XI) are involved in vision to clinic. Vision Dev & Rehab 2015;1(1):14-29. and visual processing in some way.10 In addition, 30-40 distinct cortical areas of the brain receive Keywords: attention, visual-evoked potential and/or process visual information.11 Thus, it (VEP), mild traumatic brain injury (mTBI) is not surprising that a range of visual deficits frequently occur following mTBI.7,8,12,13

14 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 than one-half century later, Klimesch30 suggested that human thalamo-cortical attention could be probed by assessing the alpha band. High alpha power occurs during the “relaxed”, eyes-closed attentional state. It is associated with synchronous neuronal cortical activity. In contrast, low alpha power occurs during visual stimulation with the eyes-open. It is associated with asynchronous neuronal cortical activity30 (See Figure 1). Most importantly, attenuation of the alpha band power occurs with the eyes- open versus eyes-closed condition: inability to Figure 1: Alpha attenuation for the eyes-closed (neuronal synchronization) and the eyes-open (neuronal desynchron­ suppress alpha during the eyes-open condition ization) conditions. X and Y axes represent the alpha band suggests an attentional deficit 24-27,31. Thus, frequency (Hz) and power magnitude (µV2), respectively. assessing alpha band neuronal activity provides a direct route to probe the attentional state of One of the most common problems in mTBI an individual objectively . is a presence of a general/visual attentional Two primary researchers have assessed deficit 8,14. -16 Attentional deficits, both general visual/general attention directly from the visual and visual, occur in approximately­ 50-60% cortex (V1). Fuller24 investigated attention using of the TBI population.17,18 Symptoms include the EEG method at a frequency band of 0.5- problems reading and slow visual information 30 Hz in 10 children with learning disability processing, as well as visual distractibility.12-14,19 (LD)/“minimally brain-damaged” (MBD). They Thus, such a deficit will adversely effect activities were compared with 11 normal, age-matched of daily living (ADLs),18 as well as rehabilitative children. The alpha band (i.e., 8-13 Hz) was progress.20 extracted from the overall EEG band (0.5-30 Different cortical (i.e., visual cortex, frontal, Hz). Then, the mathematical technique of power and parietal lobes) and subcortical (i.e., spectrum analysis32 (described in the Methods thalamus) areas of the brain are involved in section) was applied to quantify the response. To general and visual attentional processing,16,21 prevent any residual visually-based attentional with visual attentional processing initiated in aspects from contaminating the responses, the the primary visual cortex (V1).22,23 Disruption alpha power was recorded with the eyes-closed to any of these regions following a concussion/ in a relaxed state for 5 minutes prior to actual mTBI will likely cause an attentional deficit.8,14 -16 testing. Then, a cognitive demand was added Therefore, using the visual evoked potential to the eyes-closed condition; they performed (VEP) technique to assess attention objectively simple addition, recall of common objects, and and rapidly at the V1 level provides critical, as a word problem task during the subsequent well as very early, information regarding the testing. Fuller24 derived and calculated the human attentional state.24-28 “alpha attenuation ratio”. That is, the average There is a long history of using objective alpha power measured during the cognitively- techniques to assess human visual/general demanding eyes-closed condition was divided attention, with emphasis on the attentionally- by the average alpha power measured during related alpha band activity (8-13 Hz) of eyes-closed “resting” condition. He found that the electro-encephalograph (EEG). Berger29 an attenuation ratio of <1.00 suggested an was the first to investigate the alpha band ability to dampen, or suppress, alpha activity electrophysiologically in the human brain. More during this more cognitively-demanding, eyes-

15 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Table 1: Attentional Adult ADHD Self-Report Scale (ASRS) they were able to attenuate their alpha activity Part A and Visual Search and Attention Test (VSAT) score for each individual with mTBI in the Experiment #2. during reading. This suggested improvement in visual attention, which appeared to be related Subjects ASRS Part A VSAT Percentile Questionnaire Score Score with an improvement in reading ability and S1 13 81 basic oculomotor control. S2 11 77 The purpose of the present paper is to review S3 16 95 recent studies from our laboratory on the topic S4 21 93 of human attention as assessed objectively using S5 25 90 the VEP approach. Three experiments will be S6 28 75 reviewed, with details provided in the original S7 20 31 references: S8 17 93 S9 14 12 Experiment #1: Objective assessment of the S10 22 6 human visual attentional state.26 S11 26 87 Experiment #2: Objective assessment of S12 25 1 S13 25 65 attention in mild traumatic brain injury (mTBI) 35 S14 20 15 using the visual-evoked potential (VEP). S15 22 46 Experiment #3: Effect of oculomotor vision S16 8 79 rehabilitation on the visual-evoked potential­ Bold, italics subjects (S) represent those with a self-reported visual attentional deficit. and visual attention in mild traumatic brain injury (mTBI).28 closed condition, as predicted to be the case for those with normal attention. Fuller24 found Methods that 81% of the normal children exhibited an Subjects average attenuation ratio of 0.91, whereas Subjects participating in each experiment 80% of the LD/MBD children had an average were as follows: Experiment #1 included 18 attenuation ratio of 1.01. Thus, as compared visually-normal adults (mean = 24.0 years, SEM to the normal children, those with LD/MBD = 0.5 years); Experiment #2 included 16 adults were not able to suppress their alpha activity with mTBI, 11 with a self-reported attentional as well during the cognitively-demanding, eyes- deficit18 (mean age = 38.0 years, SEM = 4.8 years) closed condition. Similar results were found by and 5 without (mean age = 29.8 years, SEM = Ludlam.25 He used the VEP method to assess 2.2 years); and Experiment #3 included 7 adults two children with clinically-diagnosed “reading with mTBI (mean age = 29.5 years, SEM = 4.3 disability”. Alpha-band attenuational ability was years), 4 with a self-reported attentional deficit assessed under two conditions before and after (See Table 1 of Reference #28). The attentional conventional, oculomotor-based, vision therapy. information of the subjects was consistent with First, with the eyes closed, and second with the their clinical case history taken by an experienced eyes open as they read from a book. Before neuro-optometrist and a social worker in the therapy, neither child was able to attenuate college’s brain injury clinic, as well as with other alpha activity during the reading task, as would supporting medical and neuropsychological be the case in normal children without reading documentation. All individuals with mTBI disability. This suggested the presence of an received their head injury at least nine months attentional deficit. Then, they underwent vision prior to testing, which exceeded the natural therapy to remediate their oculomotor-based recovery period.36 Visually-normal subjects were reading deficit, which indirectly acts to improve recruited from the student, faculty, and staff at general and visual attention.33,34 After therapy, the State University of New York (SUNY), State

16 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Figure 2: The DIOPSYSTM NOVA-TR system used for the Figure 3: Extraction of the individual alpha power responses VEP testing. (8-13 Hz, µV2) (right) from the complex VEP waveform (left) using the mathematical techniques of Fourier analysis and power spectrum analysis. College of Optometry. Individuals with mTBI were obtained from the Raymond J. Greenwald of VEP studies.26-28,35,37 The Diopsys company Rehabilitation Center (RJGRC)/Brain Injury developed a custom-designed software pro­ Clinic at the SUNY, State College of Optometry gram to measure quantitatively the alpha with full medical documentation. Both visually- power responses via power spectrum analysis normal individuals and those with mTBI had (Dumermuth and Molinari, 1987).32 The power corrected visual acuity of 20/20 or better in spectrum analysis filters and extracts the power each eye at both distance and near. Exclusion (unit = µV2) of each alpha single frequency (i.e., criteria included a history of seizures, constant 8, 9, 10, 11, 12, and 13 Hz) that is embedded strabismus, and amblyopia, as well as any type in the overall complex VEP response waveform of ocular, systemic, or neurological disease. using Fourier analysis38 (Figure 3). It calculates These studies were approved by the Institutional the magnitude of the signal independently at Review Board (IRB) at the SUNY, State College each alpha frequency, and then provides a bar of Optometry. All subjects provided written graphical display of the power at each frequency. informed consent. Procedures Apparatus Vep and Alpha Recordings The DIOPSYSTMTM NOVA-TR VEP system The VEP and alpha recordings were (Diopsys. Inc., Pine Brook, NJ) was used for the assessed by using three standard GRASS (Grass experiments to measure VEP amplitude, latency, Technologies, Astro-Med, Inc., West Warwick, and alpha band power (Figure 2). This system RI) gold cup electrodes (i.e., active, reference, generated an alternating, black-and-white and ground), each of 1 cm diameter in size. checker­­board pattern stimulus. It recorded The following attentional test conditions were responses from the primary visual cortex (V1), performed to measure the VEP responses and which then analyzed/stored the real-time data. to modulate the attentional state to assess the The system consists of a 17” LCD stimulus test correlated alpha power responses: monitor with a refresh rate of 75 Hz, and a 1. Central VEP [baseline, “eyes open (EO)”] single computer processing unit which controls – The system’s standard, conventional the entire VEP system. This system has been black-and-white, checkerboard, pattern approved by the FDA, and it has been used in reversal VEP test stimulus was employed our laboratory for the last 4 years for a variety (17º H x 15º V, 20 min arc check size at

17 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 1 meter distance, 85% contrast, 74 cd/ trial, respectively.39 Different numerical m2 luminance, 1 Hz temporal frequency, starting positions were used to prevent 20 second trial duration, binocular memorization. It was predicted that with viewing with spectacle correction, and a the added cognitive task, the alpha power chinrest/headrest for stability). Subjects would be attenuated due to the increase were instructed to gaze at the center of in non-visual attentional demand, as the display screen on a small target. This compared to the eyes-closed condition. condition was performed to assess the VEP amplitude and latency, as well as the Additionally, a passive rapid-serial visual alpha (8-13 Hz) power responses. It was presentation (RSVP) gazing task,40 and two active also conducted to assure VEP response RSVP tasks, were performed in Experiment #1 normalcy. During this condition, it was (details are provided in Willeford et al.26 2013a). predicted that the alpha power would The Willeford et al.26 study found no significant be reduced if the normally-occurring, differences in alpha power values for these eyes-open, visual damping process were three RSVP conditions, as compared to the EO present24,30 (Figure 1). condition. Therefore, only the EO, EC, and ECNC conditions were performed in the Experiment 2. “Eyes-closed (EC)” (“relaxed”, reduced #2, and only the EO and EC conditions were attentional state) – Subjects were performed in Experiment #3 before and after the instructed to close their eyes, relax, and oculomotor vision rehabilitation (OVR), as these “clear their mind”, for 2 minutes before were the most robust and consistent attentional starting the VEP trials. This was done to test conditions. attain a relaxed attentional state, which would help them in attaining maximum Subjective Attentional Testing alpha power.24,26 During the trial, they Visual Search and Attention Test (VSAT) were requested to imagine “looking” The Visual Search and Attention Test, or straight ahead where the central fixation VSAT (© Psychological Assessment Resources, target was originally presented during the Inc.) involves a visual search and cancellation initial eyes-open condition, with minimal task, which assesses an individual’s sustained saccadic eye movements to avoid artifacts attentional ability.41 Sensitivity and specificity are in the recordings. During this condition, 88 and 86, respectively, and test-retest reliability it was predicted that the alpha power is 0.95. The subject was provided 60 seconds would increase, as found in normal to complete each of two trials. The results of individuals,24,30 as compared to both the the two test trials were averaged to calculate EO and the ECNC (see below) conditions the mean VSAT raw score for each subject. The (Figure 1). raw score was then compared with the age- matched normative table to determine the VSAT 3. “Eyes-closed number counting (ECNC)” percentile score. The VSAT abnormal scores (increased attentional demand) – In include the 1st and 2nd percentile, with the this condition, subjects were requested to 3rd through 16th percentiles being considered close their eyes, as they did in the above borderline abnormal. This test of attention was eyes-closed condition (#2). They were then used in all three experiments. instructed to perform a cognitive task (i.e., mental arithmetic).24 This con­sisted Adult ADHD Self-Report Scale (ASRS) of counting backwards silently, starting The Adult ADHD Self-Report Scale (ASRS) from 100, 96, 94, 92, and 90 for each questionnaire was developed by the World

18 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Health Organization (WHO) to screen adults component.34,35 OVR was performed twice a for attention-deficit/hyperactivity disorder.42 week for six weeks for a total of 9 hours, 3 Sensitivity and specificity are 56 and 98, hours for each oculomotor system. There was respectively, and test-retest reliability is 0.87. Part also a similar placebo arm to the protocol (see A (9 questions) of this questionnaire dealing with Thiagarajan43-48 for details). attention was used in Experiment #2 to detect and differentiate mTBI with versus without Data Analysis an attentional deficit. Each question is scored GraphPad Prism 5.04 software was used to based on “how they have felt and conducted perform the graphical and data analyses. One- themselves” over the past 6 months. The rating way and two-way ANOVAs were performed, scale ranged from 0-4, with 0 signifying “never as well as t-tests, to analyze the data. The felt and conducted” to 4 signifying “very often coefficient of variation (CV = standard deviation felt and conducted”. Scores can fall into three ÷ mean) of the alpha wave responses was pre-specified categories: 0-16, 17-23, and 24 or calculated to assess repeatability.26,27 The CV greater, signifying that the subject was unlikely, value can range from 0.00 to 1.00.49 This likely, and highly likely to manifest an attentional value represents the intra-subject variability: the deficit, respectively. The ASRS was performed smaller the value, the less the variability, and only in Experiment #2. the better the repeatability.

Alpha Attenuation Ratio (AR) Results Two alpha attenuation ratios (ARs) related Experiment #1: Objective assessment of the to the attentional state were calculated.24,26 The human visual attentional state.26 first was the measured alpha power (µV2) during the “eyes-closed (EC)” condition divided by the VEP responses measured alpha power during the “eyes-open The group mean VEP amplitude (18.27 µV, (EO)” condition. An EC ÷ EO AR value of ≥2.00 SEM = 1.80) and latency (104.10 ms, SEM = suggested the presence of normal attention.26,27 0.68) values were found to be within normal The second AR was calculated as the measured limits for our laboratory. alpha power during the “eyes-closed number counting (ECNC)” condition divided by the measured alpha power during the “eyes-closed (EC)” condition. Fuller24 found that an ECNC ÷ EC AR of <1.00 suggested the presence of normal attention.

Oculomotor Vision Rehabilitation (OVR) and the VEP Oculomotor vision rehabilitation (OVR), i.e., vision therapy, was provided to the seven individuals with mTBI in Experiment #3 using a crossover, interventional experimental design clinical trial. The OVR consisted of training each of the three oculomotor systems, i.e., Figure 4: Average alpha-power values across the six test conditions at each frequency (mean, +1 SEM). (Reprinted version, vergence, and accommodation, with with permission from Willeford et al.26, Documenta such training indirectly including an attentional Ophthalmologica)

19 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Power spectrum The group mean power spectrum value at each alpha band frequency (i.e., 8, 9, 10, 11, 12, and 13 Hz) for the 6 attentional test conditions are presented in Figure 4. The eyes-closed (EC) and eyes-closed number counting (ECNC) values averaged across the 6 alpha frequencies were found to be significantly higher than for the other 4 eyes-open (EO) conditions (p < 0.05). In addition, the mean EC ÷ EO AR was higher than 2.00, mainly at 10 Hz (2.17, range = 0.88 to 4.04) and 11 Hz (2.93, range = 1.02 to 14.94). The mean ECNC ÷ EC AR was found to be Figure 5: Correlation between the attenuation ratio (AR) lower than 1.00 at all alpha frequencies, except (EC ÷ EO) at 10 Hz and the VSAT percentile score. (Reprinted with permission from Willeford et al.26, Documenta 24 11 Hz. Both group AR values were normal. Ophthalmologica) The mean coefficient of variation (CV) was used to assess repeatability. CV values ranged from 0.48 to 0.64 for the alpha response VEP responses averaged across all frequencies and subjects, The group mean VEP amplitude (19.20 µV, which suggested reasonably good repeatability. SEM = 2.38) and latency (108.86 ms, SEM = 1.84) values were found to be within normal Visual Search and Attention Test (VSAT) limits for our laboratory. The VSAT percentile scores ranged from the 11th to the 95th percentile (mean = 52.61, Power Spectrum SEM = 29.32). Each subject’s score was above The group mean power spectrum values the abnormal 2nd percentile. Three scored at each alpha band frequency (i.e., 8, 9, 10, in the borderline range (i.e., 11th, 12th, and 11, 12, and 13 Hz) for the 3 attentional test 16th percentile). However, the ARs between conditions for individuals with mTBI and an these three borderline subjects and the top attentional deficit are presented in Figure 6A. three performing subjects were not significantly The ECNC power values averaged across the 6 different (p > 0.05). alpha frequencies were found to be significantly higher than for the EO and EC conditions (p Correlations < 0.05), thus demonstrating the presence of Linear regression analysis was used to assess abnormal dampening with the eyes closed. the correlation between the alpha EC ÷ EO The group mean power spectrum value at ARs and VSAT percentile scores at each alpha each alpha band frequency (i.e., 8, 9, 10, 11, 12, frequency. There were significant correlations at and 13 Hz) for the 3 attentional test conditions 8, 9, and 10 Hz (r = +0.55 to +0.69, all p ˂ for individuals with mTBI but without an 0.05). The correlation was found to be highest attentional deficit are presented in Figure 6B. The at 10 Hz (r = +0.69), as shown in Figure 5. EC and ECNC conditions power values averaged across the alpha frequencies were found to be Experiment #2: Objective assessment of at­ significantly higher as compared to the average ten­tion in mild traumatic brain injury (mTBI) EO condition (p < 0.05), thus demonstrating using the visual-evoked potential (VEP).35 the presence of normal attentional abilities,

20 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Figure 6: The group mean power spectrum value (µV2) at each alpha band frequency (8-13 Hz) for the 3 test conditions. Plotted is the mean +1 SEM. (A) Individuals with mTBI and an attention deficit, (B) Individuals with mTBI without an attention deficit. Symbols: EO = eyes-open, EC = eyes-closed, and ECNC = eyes-closed number counting, conditions.

Figure 7: The group mean alpha attenuation ratio (AR) (EC ÷ EO) for each alpha frequency. Plotted is the mean +1SEM. Dashed line = lowest normative AR level. (A) Individuals with mTBI and an attention deficit, (B) Individuals with mTBI without an attention deficit. similar to that found in Experiment #1 in the the EO and EC power values in mTBI with an visually-normal population for these same three attentional deficit (p < 0.05), thus suggesting conditions (Figure 4).26 normal attention in the former group. Comparisons were also performed between The coefficient of variation (CV) analysis was those having mTBI with versus without an used to assess repeatability. CV values for all attentional deficit for the EO, EC, and ECNC parameters were typically found to be extremely test conditions, with the power values averaged small (median = 0.09, range = 0.003 to 0.58) across the 6 alpha frequencies. The EC and ECNC in the two mTBI subgroups, thus suggesting power values in mTBI without an attentional excellent repeatability. deficit were significantly higher, as compared to

21 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Figure 8: The combined attenuation ratio (AR) (EC ÷ EO) across the alpha frequency band (8-13 Hz) for each subject. Plotted is the mean +1SD. Dashed line = lowest normative AR level. (A) Individuals with mTBI and an attention deficit, (B) Individuals with mTBI without an attention deficit.

Alpha Attenuation Ratio (AR): The EC ÷ EO AR for each subject was lower Individual Alpha Frequencies than the mean normative AR value of ≥2.00. The group mean EC ÷ EO AR for each alpha The group mean EC ÷ EO AR combined and frequency for individuals with mTBI and an averaged across the alpha frequency band was attentional deficit is presented in Figure 7A. The 1.01 (SEM = 0.07), with a range from 0.62 to mean EC ÷ EO AR at each alpha frequency was 1.33. In addition, the ECNC ÷ EC AR combined significantly lower (i.e., abnormal, all p < 0.05) and averaged across the alpha frequency band than the normative AR value of ≥2.00 (range = for most individuals (except subjects #12 and 0.81 to 1.36). In addition, the mean ECNC ÷ EC AR 13) was higher than the normative AR value of at each alpha frequency was significantly higher <1.00, which was abnormal. The group mean (i.e., abnormal, all p < 0.05) than the normative ECNC ÷ EC AR combined across the alpha AR value of <1.00 (range = 1.27 to 2.24). frequency band was 1.79 (SEM = 0.96), with a The group mean EC ÷ EO AR for each alpha range from 0.86 to 4.33. frequency for individuals with mTBI but without The EC ÷ EO AR combined and averaged an attention deficit is presented in Figure 7B. across the alpha frequency band (i.e., from 8-13 The mean EC ÷ EO AR at 9, 10, 11, and 12 Hz Hz) for each individual with mTBI but without an was ≥2.00 (range = 1.59 to 3.92), which was attentional deficit is presented in Figure 8B. The normal.26 In addition, the mean ECNC ÷ EC AR EC ÷ EO AR was ≥2.00, which was normal.26 The at 8, 9, 10, 11, and 12 Hz was <1.00 (range = group mean EC ÷ EO AR combined across the 0.59 to 1.10), which was also normal.24,26 alpha frequency band was 2.19 (SEM = 0.03), with a range from 2.07 to 2.18. In addition, the Alpha Attenuation Ratio (AR): Combined ECNC ÷ EC AR combined and averaged across Across the Alpha Frequency Band (8-13 Hz) the alpha frequency band for each individual The EC ÷ EO AR combined and averaged was <1.00, which was normal 24,26. The group across the alpha frequency band (i.e., from mean ECNC ÷ EC AR combined across the alpha 8-13 Hz) for each individual with mTBI and an frequency band was 0.806 (SEM = 0.02), with a attentional deficit is presented in Figure 8A. range from 0.71 to 0.86.

22 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 There was a significant difference between attentional deficit (p < 0.05), thus suggesting those having mTBI with versus without an presence of an attentional deficit. attentional deficit for the EC ÷ EO AR combined across subjects and averaged across the alpha Correlation frequency band. It was significantly higher Linear regression analysis was performed in the mTBI subgroup without an attentional to assess the correlation between the AR, deficit (p ˂ 0.05), thus suggesting normalcy in ASRS, and VSAT for all individuals with mTBI this subgroup. (n=16). The following correlations were There was a significant difference between found be significant. First, the correlations those having mTBI with versus without an atten­ between EC ÷ EO AR and the ASRS score at tional deficit for the ECNC ÷ EC AR combined most alpha frequencies were significant: 8, across subjects and averaged across the alpha 9, 10, 11, and 12 Hz (r = -0.62 to -0.83, all frequency band. It was significantly smaller in p <˂ 0.05). The correlation was highest at mTBI without an attentional deficit (p > 0.05), 10 Hz (r = -0.83) (Figure 9). Second, the thus suggesting normalcy in this subgroup. correlations were also significant between the EC ÷ EO AR combined and averaged Visual Search and Attention Test (VSAT) across the alpha frequency band and the The VSAT percentile scores for each subject ASRS scores (r = -0.76, p < 0.05). Lastly, the are presented in Table 1. In mTBI with a self- correlation between the ECNC ÷ EO AR and the reported attentional deficit (n=11), the mean ASRS was significant only at 8 Hz (r = -0.53, VSAT percentile score was 54.72 (SEM = 10.95), p < 0.05). In contrast, there were no significant with a range from 1 to 93. In contrast, in mTBI correlations with the VSAT percentile scores. without a self-reported attentional deficit (n=5), Thus, the objective ARs were correlated with the mean VSAT percentile score was 68.80 the subjective ASRS, but not with the subjective (SEM = 14.54), with a range from 12 to 95. VSAT, attentional scores. Subjects S10 and S9 had borderline 6th and 12th percentile scores, respectively, and subject Experiment #3: Effect of oculomotor vision S12 had an abnormal 1st percentile score. rehabilitation (OVR) on the visual-evoked Comparison between the two groups for the potential and visual attention in mild VSAT scores revealed no significant difference traumatic brain injury.28 (p > 0.05).

Adult ADHD Self-Report Scale (ASRS) The Part A questionnaire scores for the ASRS test for each subject are presented in Table 1. In mTBI with a self-reported attentional deficit (n=11), the mean score was abnormal, i.e., 22.81 (SEM = 0.97), with a range from 17 to 28. In contrast, in mTBI without a self-reported attentional deficit (n=5), the mean score was normal, i.e., 12.40 (SEM = 1.36), with a range from 8 to 16. None of the scores for those with mTBI and an attentional deficit fell within the normal range. Comparison between the two Figure 9: Correlation between the attenuation ratio (AR) groups for the ASRS scores revealed that it was (EC ÷ EO) at 10 Hz and the Adult ADHD Self-Report Scale significantly higher in those having mTBI and an (ASRS) Part A questionnaire scores.

23 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 VEP Responses The group mean VEP amplitude was signifi­ cantly increased (i.e., from 17.40 to 19.15 µV), and its variability was significantly decreased (i.e., from 1.89 to 1.03 µV), following the OVR. There was no change in mean latency (i.e., before = 105.53 ms and after = 105.63 ms) and its variability (i.e., before = 1.35 ms and after = 1.64 ms) following the OVR. Latency values were the same and within the normal limits before (105 ms) and after OVR (105 ms).

Power Spectrum The group mean power spectrum values at each alpha band frequency (i.e., 8, 9, 10, 11, 12, and 13 Hz) for the EO and EC attentional test conditions for individuals with mTBI (n = 7) before oculomotor vision rehabilitation (OVR) are presented in Figure 10A. The EC power values combined and averaged across the 6 alpha frequencies were significantly higher than for the EO condition (p < 0.05). However, the AR values were only normal at two of the six individual alpha frequencies (i.e., 9 and 10 Hz). The group mean power spectrum values at each alpha band frequency (i.e., 8, 9, 10, 11, 12, and 13 Hz) for the EO and EC attentional test conditions for individuals with mTBI after oculomotor vision rehabilitation (OVR) are presented in Figure 10B. The EC power values combined and averaged across the 6 alpha frequencies were significantly higher than for the EO condition (p < 0.05). However, AR values were now normal at four of the six individual alpha frequencies (9, 10, 11, and 13 Hz). Figure 10: The group mean power spectrum value (µV2) at Most importantly, comparison of the EC each alpha band frequency (8-13 Hz) for the 2 test conditions. Plotted is the mean +1 SEM. (A) Before OVR, (B) After OVR. condition before and after OVR showed a Symbols: EO = eyes-open, and EC = eyes-closed, conditions. significant increase (p < 0.05) in the power values averaged and combined across all 6 alpha frequencies (compare Figure 10A and Alpha Attenuation Ratio (AR): 10B). In contrast, there was no difference in the Individual Alpha Frequencies EO power values before and after the OVR. The The group mean AR for each alpha frequency former result suggests increase in attentional before and after the OVR is presented in Figure ability following OVR. The latter result is 11A. The EC ÷ EO AR increased numerically at consistent with this notion. each frequency and attained the normal value

24 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Figure 11: Correlation between the attenuation ratio (AR) (EC ÷ EO) at 10 Hz and the VSAT percentile score. (Reprinted with permission from Willeford et al.26, Documenta Ophthalmologica) of 2 (with +1 SEM added to the mean) after Discussion the OVR. The EC ÷ EO AR significantly increased The findings of the three reviewed following the OVR at 3 of the 6 alpha frequency studies26,28,35 clearly demonstrate that the sub-bands (i.e., 10, 11, and 13 Hz) (all p < 0.05), VEP technique can be used to detect and thus suggestive of increased attention following assess attention in both the visually-normal the OVR. and mTBI populations in a rapid, repeatable, quantitative, and objective manner. Further­ Alpha Attenuation Ratio (AR): Combined more and very importantly, the VEP approach Across the Alpha Frequency Band (8-13 Hz) was able to differentiate between the visually- The EC ÷ EO AR combined and averaged normal and mTBI groups, as well as between across the alpha frequency band (i.e., from individuals having mTBI with versus without an 8-13 Hz) before and after the OVR is presented attentional deficit. Of particular note, an increase in Figure 11B for each subject. The EC ÷ EO in attentional state was found in those with mTBI AR increased numerically in each subject and following successful OVR. The attenuation ratio normalized in all but one subject (S6). There (AR) metric was found to be useful to assess and was also a significant increase in the combined detect an individual’s attentional state in both alpha EC ÷ EO AR following the OVR (p < 0.05), the visually-normal and mTBI populations. Of thus suggestive of increased attention following interest, and a critical finding, the objective ARs the OVR. were correlated with the subjective attentional tests. Lastly, these findings demonstrate that VSAT Pre/Post Scores human attention could be assessed as early as There was a significant increase (p < 0.05) the primary visual cortex (V1) in both the VN and in the mean VSAT score following the OVR. Pre- mTBI populations. OVR, it was 40.25 +12.31 (SEM), whereas post- OVR, it was 59.50 +9.28 (SEM).28 Alpha Attenuation Ratio (AR) These findings confirmed that the AR could be used as a clinical metric to assess

25 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 one’s attentional state objectively. Willeford et Oculomotor Vision Rehabilitation al.26 found that an EC ÷ EO AR of ≥2 and an (OVR): VEP and Alpha Responses ECNC ÷ EC AR of <1 was suggestive, and even Yadav et al.28 demonstrated objectively the predictive, of having normal attention. The ARs positive effect of OVR at the visuo-cortical level in our studies were consistently found to be in those with mTBI. There was enhancement abnormal in those with mTBI and an attentional in both the VEP and alpha responses following deficit, and normal in individuals with mTBI but the OVR. The VEP amplitude increased, and without an attentional deficit. Furthermore, the its variability decreased, with correlated significant increase in the EC ÷ EO AR found improvement in alpha-based attentional following OVR suggests a positive impact on the state. As mentioned earlier, all OVR has an mTBI attentional state, as well as demonstrating embedded attentional training component by residual visual neuroplasticity, even in an adult, its very nature:33,34 patients were instructed compromised brain. to remain vigilant during the specified vision therapy tasks involving both detection and Subjective Attention Test (VSAT and ASRS) discrimination of the visual stimulus attributes Two subjective attentional tests were (e.g., blur). Therefore, an increase in alpha performed: VSAT and ASRS. The VSAT per­centile power during the EC condition following the scores were correlated with the AR values in OVR was not surprising, and in fact, expected. the visually-normal group, but not in the mTBI Furthermore, the subjective VSAT percentile population; rather here the ASRS scores were scores also increased significantly following correlated with the AR values in the mTBI the OVR. Improvement in the objectively- group. This discrepancy might be attributed to based attentional parameters at the V1 cortical one or more of the following reasons. Due to level was consistent with the clinically-based larger spread of AR values in the visually-normal subjective attentional test results, thus lending as compared to the mTBI group, there would credibility to each approach. be more likelihood of a significant correlation. However, we believe that other factors are Neurophysiological Mechanism more likely to be involved. Both the AR values A possible neurophysiological mechanism and the VSAT percentile scores were found to underlying these findings is based on the concept be within normal limits in the visually-normal of synchronous versus asynchronous neuronal group. In contrast, the AR values were in the activity. Such activity occurs at the primary abnormal range, whereas the VSAT scores were visual cortex (V1) level during modulation of in the normal range, in those with mTBI having one’s attentional state (e.g., eyes-closed versus an attentional deficit. The ASRS questionnaire eyes-open condition). was able to differentiate between mTBI with What might occur during the EC relaxed/ versus without an attentional deficit 100% of low attentional demand condition? Klimesch30 the time, but this was only true 18% of the (1999), and others,50,51 suggested that in time with the VSAT. In addition, the EC ÷ EO AR individuals with normal attention, synchronous values were correlated with the ASRS score at neuronal activity occurs. This was presumably nearly all frequencies (except at 13 Hz), whereas due to oscillation of a large number of neurons the ECNC ÷ EC AR values were correlated only having the same phase and frequency. These at the 8 Hz alpha frequency. Overall, these synchronous oscillations can be appreciated findings suggest that the ASRS questionnaire quantitatively as reflective of increased alpha and the EC ÷ EO AR are better to detect and band power. This oscillatory activity is believed assess individuals with mTBI for presence of a to “block” information processing from general/visual attentional deficit. occurring. In contrast, it was suggested that in

26 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 those individuals with mTBI and an attentional 2. Subjective test – The Adult ADHD deficit, asynchronous activity occurs during Self-Report Scale (ASRS) Part A attention the EC (“relaxed”) attentional state, and thus questionnaire should be administered to these individuals cannot “block” information assess the attentional state. processing from occurring. The asynchronous 3. Objective attentional test – The neuronal activity would cause attenuation, or following two test condition should be suppression/damping, of the alpha band power performed to measure the VEP and alpha via signal cancellation.52 band power responses to calculate the AR The opposite is believed to occur in the EO value: condition. In individuals with normal attention, A. Eyes open (EO) asynchronous neuronal activity is believed B. Eyes-closed (EC) to occur during the EO condition, whereas synchronous neural activity is believed to occur Number of trails – 5 trials, each of 20 during the ECNC condition. This asynchrony seconds, per test condition should be performed during the former condition is believed to be and averaged. due to oscillation of a large number of neurons The EC ÷ EO AR should be quantified at each with different phases and frequencies, which alpha band, as well as combined and averaged occurs due to processing of the more visually- across the alpha frequency bands. These based and cognitively-demanding information. objective findings should be consistent with the This asynchrony causes attenuation of the alpha individual’s case history and the ASRS Part A band power, again via signal cancellation.52 questionnaire scores, and furthermore assistive In individuals with mTBI and an attentional in making the final diagnosis with a high degree deficit, asynchronous activity occurs during all of certainty. Our proposed objective protocol three conditions, and thus presence of relative would be beneficial to clinicians in assessing attenuation. The findings of the present studies and detecting one’s attentional state rapidly, are consistent with the proposed mechanism of quantitatively, reliably, and objectively. Due to its Klimesch,30 and others.50,51 objective nature, the proposed attentional test protocol may also be helpful in the cognitively- Neurophysiological Substrates impaired and non-verbal populations, as well as There are several neural substrates that are in the pediatric population, in which attentional likely to contribute to the VEP/alpha response. deficit (e.g., ADHD) is suspected. The software For the EO condition, the contributors include for the alpha-band assessment of attention is V1-V4 and the thalamus.53 For the EC condition, available from the Diopsys company (www. the contributors include the thalamo-cortical diopsys.com). pathway.30 Other neural regions may participate, but this remains speculative. Study Limitations There were two possible study limitations. Clinical Implications First, there were a relatively few number of sub- The findings of these three studies were jects with mTBI in the OVR experiment. Second, instrumental in formulating a clinical attentional these studies included only those with mTBI, and test protocol in those with mTBI, as described not individuals with moderate or severe TBI. below: 1. Case history – A detailed case history Conclusions regarding visual/general attention should be The present findings clearly demonstrate taken. that the VEP, an objective approach, can be used clinically to rapidly and quantitatively detect and

27 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 assess attention in the mTBI population. This was 4. Werner C, Englehard K. Pathophysiology of traumatic achieved by measuring the alpha power under brain Injury. Br J Anaesth 2007;99:97-104. different attentional states and calculating 5. Greve MW, Zink BJ. Pathophysiology of traumatic brain injury. Mt Sinai J Med 2009;76:97-104. the respective alpha AR values, which were 6. Hurley RA, McGowan JC, Arfanakis K, et al. Traumatic correlated with the subjective attentional tests axonal injury: novel insights into evolution and identifi­ scores. The AR values were found to be beneficial cation. J Neuropsychiatry Clin Neurosci 2004;16:1-7. in differentiating between the visually-normal 7. Suchoff IB, Ciuffreda KJ, Kapoor N, eds. Visual and and mTBI populations, as well as between those Vestibular Consequences of Acquired Brain Injury. Santa Ana, CA: Optometric Extension Program Foundation; having mTBI with versus without an attentional 2001. deficit. The increase in the mean VEP amplitude 8. Suter PS, Harvey LH, eds. Vision Rehabilitation. following the OVR suggested enhanced and Multidisciplinary Care of the Patient Following Brain more synchronized neural activity within V1. Injury. New York, NY: Taylor and Francis Group; 2011. Similarly, the increase in the mean VSAT score 9. Zasler ND, Katz DI, Zafonte RD, eds. Brain Injury Medicine, following the OVR suggested enhancement Principles, and Practice New York, NY: Demos Medical Publishing; 2007. in attentional ability, which is consistent with the notion that OVR has an embedded 10. Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. Philadelphia, PA: Wolters Kluwer Health/ attentional component. The VEP technique has Lippincott Williams and Wilkins; 2010. the potential to become an additional tool in 11. Helvie R. Neural substrates of vision. In: Suter PS, Harvey the clinician’s diagnostic armamentarium for LH, eds. Vision Rehabilitation. Multidisciplinary Care of objectively-based attentional assessment in the the Patient Following Brain Injury. New York, NY: Taylor and Francis Group; 2011: 45-76. optometric practice. 12. Ciuffreda KJ, Ludlam DP. Conceptual model of optometric vision care in mild traumatic brain injury. J Behav Optom Acknowledgments 2011;22:10-12. We would like to thank the College of 13. Ciuffreda KJ, Ludlam DP, Thiagarajan P. Oculomotor Optometrists in Vision Development (COVD) diagnostic protocol for the mTBI population. Optometry for funding to K.J.C and N.K.Y, the Army/ 2011;82:61-63. DoD for Awards (W81XWH-10-1-1041 and 14. Cicerone KD. Attention deficits and dual task demands after mild traumatic brain injury. Brain Inj 1996;10:79-89. W81XWH-12-1-0240) to K.J.C, and the SUNY, Graduate Program for funding this project. 15. Chan RC. Attentional deficits in patients with persisting concussive complaints: a general deficit or specific We would also like to thank the American component deficit? J Clin Exp Neuropsychol 2002;24:1081- Optometric Foundation (AOF) for awarding the 1093. Ezell Fellowship to N.K.Y and P.T. Lastly, we are 16. Halterman CI, Langan J, Drew A, et al. Tracking the grateful to DIOPSYS Inc., Pine Brook, New Jersey recovery of visuospatial attention deficits in mild traumatic brain injury. Brain 2006;129:747-753. for providing the VEP system for these studies. 17. Lew HL, Poole JH, Guillory SB et al. Guest editorial: Persistent problems after traumatic brain injury: The need References for long-term follow-up and coordinate care. J Rehabil 1. Okie S. Traumatic brain injury in the war zone. N Engl J Res Dev 2006;43:vii-x. Med 2005;352:2043-2047. 18. Barlow-Ogden K, Poynter W. Mild traumatic brain injury 2. Marr AL, Coronado VG, ed. Central Nervous System Injury and posttraumatic stress disorder: Investigation of visual Surveillance Data Submission Standards - 2002. Atlanta, attention in Operation Iraqi Freedom/Operation Enduring GA: Dept. of Health and Human Services (US), Centers for Freedom Veterans. J Rehabil Res Dev;49:1101-1114. Disease Control and Prevention, National Center for Injury 19. Whyte J, Fleming M, Polansky M et al. The effects of Prevention and Control; 2004. visual distraction following traumatic brain injury. J Int 3. Thiabault LE, Gennareli TA. Brain injury: an analysis of neural Neuropsychol Soc 1998;4:127-136. and neurovascular trauma in the non-human primate. 20. Ylvisaker M. Context-sensitive cognitive rehabilitation Annu Proc Assoc Adv Automot Med 1990;34:337-351. after brain injury: Theory and practice. Brain Impair 2003;4:1-16.

28 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 21. Fan J, McCandliss BD, Sommer T et al. Testing the 39. Smith A. The serial sevens subtraction tests. Arch Neurol efficiency and independence of attentional networks. J 1967;17:78-80. Cogn Neurosci 2002;14:340-347. 40. Jing Xu, Ciuffreda KJ, Chen H et al. Effect of retinal 22. Somers DC, Dale AM, Seiffert AE et al. Functional MRI defocus on rapid serial visual presentation (RSVP). J Behav reveals spatially specific attentional modulation in Optom 2009;20:67-69. human primary visual cortex. Proc Natl Acad Sci U.S.A. 1999;96;1663-1668. 41. Trenerry MR, Crosson B, DeBoe J, Leber WR. Professional manual: visual search and attention test. Lutz, FL: 23. Kastner S, Ungerleider LG. Mechanism of visual Psychological Assessment Resources; 1989. attention in the human visual cortex. Annu Rev Neurosci 2000;23:315-341. 42. Kessler RC, Adler L, Ames M et al. 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29 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Article: Assessing Hemianopia Objectively in Stroke Patients Using the VEP Technique: A Pilot Study Naveen K. Yadav, B.S. (Optom), MS, PhD Kenneth J. Ciuffreda, OD, PhD SUNY State College of Optometry, Department of Biological and Vision Sciences

abstract The purpose of this pilot study was to assess hemianopic visual field defects objectively in individuals with stroke using the pattern, visual-evoked potential (VEP) technique. Subjects were comprised of 5 adults with documented hemianopic visual field defects. The central field and the intact hemi-field VEP amplitudes were significantly larger than found in the hemianopic field (p < 0.05). However, latency values were similar (p > 0.05). The objective pattern VEP has the potential to be used rapidly and reliably to detect for the presence of hemianopic visual field defects in stroke patients.

Introduction insufficient supply of oxygen (i.e., anoxia) via Stroke is one of the leading causes of death blood circulation to the affected brain cells. This and disability in the adult population of the oxygen deprivation causes insult and frequently United States.1 Common risk factors include death to the underlying brain tissues, with hypertension, diabetes, high cholesterol levels, resulting impairment of its neurological control smoking, and atrial fibrillation.2 function. Stroke can either be ischemic or hemor­ Stroke frequently results in impaired visual rhagic. According to the American Stroke functioning to a constellation of areas,4,5 such as Association, 83% of strokes are ischemic, and reading and visual scanning ability. Visual-field 17% are hemorrhagic.3 Stroke produces an defects (e.g., hemianopia), at times with visual neglect, are common visual sequelae to a stroke, Correspondence regarding this article should be emailed or cerebrovascular accident (CVA).6,7 Hemianopia to Naveen K . Yadav at [email protected] or call 212-938-5774 . All statements­ are the author’s personal refers to a physiologically-based phenomenon opinion and may not reflect the opinions of the College of involving loss of one-half of the lateral visual- Optometrists in Vision Development, Vision Development field and for which the individual is fully aware & Rehabilitation or any institution or organization to of its absence. In contrast, visual neglect refers which the author may be affiliated . Permission to use to a perceptually-based phenomenon in which reprints of this article must be obtained from the editor . Copyright 2015 College of Optometrists in Vision the individual is “unaware” of the loss of one Development . VDR is indexed in the Directory of Open half of their lateral visual-field.8 Hemianopia Access Journals . Online access is available at covd.org . and visual neglect can be present together, or https://doi.org/10.31707/VDR2015.1.1.p30 . independently. Either will adversely affect one’s Yadav N, Ciuffreda K. Assessing hemianopia objectively activities of daily living (ADLs), as well as have in stroke patients using the vep technique: a pilot study. an adverse impact on one’s vocational and Vision Dev & Rehab 2015;1(1):30-38. avocational goals, and rehabilitative progress.9 Since stroke patients with hemianopia Keywords: attention, visual-evoked potential frequently have fixational eye movement, (VEP), mild traumatic brain injury (mTBI) attentional, and/or cognitive deficits, clinical visual field perimetry may not always be an 30 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 optimal method to investigate for the presence patients (i.e., 9 with left-visual field neglect, 7 of hemianopia.10,11 The VEP is a logical adjunct without neglect), and 16 visually-normal subjects. technique to assess for hemianopia in the Vertical sinusoidal gratings of 0.56 cycles per CVA population. It is an objective, rapid, degree were used with a field size of 12.8H X and repeatable method.11,12 Furthermore, it 32.8V degrees. The gratings were sinusoidally- circumvents, or at least minimizes, many of reversed at temporal frequencies ranging from the inherent problems associated with clinical 4-11Hz. Contrast was 32%, and luminance was visual field testing. The VEP method does not 150 cd/m2. They assessed both VEP amplitude demand prolonged attention or highly accurate and latency. There was no significant effect on fixation, as compared to conventional perimetry, either parameter in the neglected and normal especially over a relatively long test duration hemifields. The same was true in hemianopic (i.e., 5 minutes or more for perimetry versus 20 patients without neglect, as well as in the seconds for each VEP trial). visually-normal subjects. However, they did find There are a paucity of relevant studies which that the VEP amplitude was slightly lower at have used the VEP method to assess hemianopia higher temporal frequencies (e.g., 8 Hz) in those in CVA patients. The results are equivocal, as with a neglected left-visual field, as compared described below. to their normal right-visual field. Furthermore, Viggiano et al13 studied 10 individuals with with increase in temporal frequency, they found CVA having left-field hemianopia and visual markedly delayed latencies of ~30-40 ms in neglect, 11 individuals with CVA having left- patients with visual neglect, as compared to field hemianopia only, and 6 visually-normal those without neglect. This study demonstrated subjects. In the first experiment, they used that individuals with visual neglect did exhibit different check sizes (12, 14, 36, 48, and 72 slowed visual processing in the visually-neglected min arc) with a constant temporal frequency of field only, at least under highly specific stimulus 4.76 Hz. In the second experiment, they used conditions, in the primary visual cortex. different temporal frequencies (1.96, 3.03, In contrast, Angelelli et al.16 measured steady- 4.76, 6.66, 8.33, and 16.66 Hz) with a constant state VEP responses in 19 right brain-damaged check size of 48 min arc. Contrast was 87%, (RBD) patients with left-sided hemianopia and and luminance was 120 cd/m2. The circular visual neglect. They also had two controls checkerboard stimulus (radius = 7.5 degrees) was groups: 15 left brain-damaged (LBD) patients presented both centrally, and in the near retinal and 12 right brain-damaged (RBD) patients, all periphery (8.5 degrees laterally). For both the with hemianopia but without visual neglect. central and near peripheral stimulus, there were They used vertical sinusoidal gratings of 0.56 no significant differences in the VEP amplitude cycles per degree with a central field size of 6H between those hemianopes with versus without X 16V degrees. The gratings were sinusoidally- visual neglect. They speculated that the reversed at 10 temporal frequencies ranging phenomenon of visual neglect was the result of from 4-10.5 Hz, with a central fixation target damage to higher-level cortical areas, and not present. Contrast was 32%, and luminance was to early primary cortical areas encompassed by 150 cd/m2. They assessed both amplitude and the underlying VEP signal region. However, they latency. Stimuli were presented either in the did not investigate latency, which may provide right (RVF) or left (LVF) visual field. They too additional information regarding any delay in found that the mean latency was significantly visual processing in these patients, as latency is delayed by approximately 25 ms in the neglected typically slowed based on other test findings.14 LVF, as compared to the normal RVF, in those Similarly, Spinelli et al.15 used the steady-state with RBD. In contrast, there was no significant VEP in 16 right-brain-injured, hemianopic stroke difference in latency in either the right or left

31 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Table 1: Demographics of stroke patients. et al.16 found that it could. Furthermore, none Subject/ Years since Type of Visual Symptoms of the studies used either low luminance and/ Age (years)/ last stroke hemianopia or low contrast stimuli to assess hemianopia, Gender which might be more sensitive to elicit presence S1/47/M 23 years Right • Reading problems (stroke at hemianopia of a visual field defect and/or visual neglect. 2 years of Therefore, this area deserves to be explored, age due to which might reveal more subtle differences early arteriovenous malformation) in the afferent visual pathway. S2/29/F 1 year Left • Reading problems Thus, the purpose of the present pilot incomplete- • Migraines study was to determine if the VEP technique hemianopia could be used to detect and assess hemianopia S3/39/F 1 year Left • Reading objectively and reliably in individuals with CVA/ hemianopia problems • Migraines stroke. More specifically, the hypothesis is that • Photosensitivity the VEP approach will be able to detect and • Visual motion assess hemianopia objectively in individuals with sensitivity stroke using more subtle stimuli, such as low S4/56/F 24 years Right • Reading hemianopia problems contrast and low luminance patterns, which has • Visual motion never been tested before in this population. sensitivity S5/62/F 2 years Right • Reading Methods (first stroke 25 hemianopia problems years ago) • Visual-attention Subjects deficit Five individuals with CVA/stroke and • Visual fatigue hemian­opia (mean age = 46.6 years, age range • Distance perception = 29 to 62 years) participated in this study: problem three with complete right hemianopia, one • Photosensitivity with complete left hemianopia, and one with • Visual motion sensitivity incomplete left hemianopia. None had visual neglect; this diagnosis was as specified in the referring clinician’s record, and it was not hemifield in the RBD and LBD groups who did reassessed by us in the present investigation. not have neglect. The VEP amplitudes were See Table 1 for subject demographics. They reduced in the hemianopic hemified in the RBD were referred with full medical documentation patients, with or without neglect. However, the to the Raymond J. Greenwald Rehabilitation VEP amplitudes were similar in both hemifields Center (RJGRC)/Brain Injury Clinic at the SUNY, in the LBD group. These results suggested that State College of Optometry from rehabilitation both visual-neglect and hemianopia could be professionals at the following institutions: detected, even at the level of the primary visual Rusk Institute of Rehabilitative Medicine at cortex (V1). These findings supported the notion NYU Medical Center, Bellevue Hospital at NYU that the VEP can be used clinically to detect Medical Center, Department of Rehabilitative and assess hemianopia and/or visual neglect in Medicine at Mount Sinai Medical Center, patients with CVA. Lenox Hill Hospital, New York Hospital, and the Based on the above 3 studies, the results are International Center for the Disabled. All had equivocal. Viggiano et al.13, and Spinelli et al.,15 corrected visual acuity of 20/20 or better in showed that the VEP could not differentiate each eye at both distance and near. Exclusion between the hemianopic and intact visual criteria included a history of seizures, constant field, which is surprising. In contrast, Angelelli strabismus, and amblyopia, as well as any

32 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 this check size has been found to be optimal in our laboratory.11 Details have been provided elsewhere.11

Stimulus The VEP amplitude and latency were assessed with binocular viewing and full distance refractive correction in place under the following three experimental conditions (See Figure 1). None of the subjects reported the VEP stimulus to be blurry. These three stimulus conditions produced the most reliable VEP response out of the possible combinations. Three trials for each test condition were performed: I. Central field [high contrast (HC) and high luminance (HL), low contrast Figure 1: Test stimulus configurations. (A) Central, VEP (LC) and high luminance (HL), low checkerboard pattern showing high contrast and high luminance conditions, (B) Hemianopic visual-field test stimu­ luminance (LL) and high contrast (HC)] – lus for high contrast and high luminance condition, and (C) A standard, central, checkerboard pattern Hemianopic visual-field test stimulus for low contrast and (17H X 15V degrees, 20 min arc check high luminance condition. All not drawn to scale. size at 1 meter, 20 second test duration, temporal frequency 1 Hz = 2 reversal/ type of ocular, neurological, and/or systemic second) with a central fixation (0.5º disease, such as macular degeneration, diameter) target was used as the baseline multiple sclerosis, and diabetes, respectively. comparison stimulus. A checkerboard The study was approved by the Institutional pattern with either low or high contrast Review Board (IRB) at the SUNY, State College levels (i.e., 20 and 85%), and with either of Optometry. Each subject provided written low or high luminance levels (i.e., 7.4 informed consent. and 74 cd/m2), was presented for each stimulus combination. Apparatus The DiopsysTM NOVA-TR system (Diopsys, II. Intact hemi-field only (HC/HL, LC/ Inc., Pine Brook, New Jersey, USA) was used HL, LL/HC) – In this condition, the to generate a checkerboard pattern stimulus checkerboard pattern was presented and analyze the VEP data. Three Grass gold- only to the intact hemianopic visual-field cup electrodes (Grass Technologies, Astro- (8.5H X 7.5V degrees) with the contrast Med, Inc., West Warwick, RI), each of 1 cm in and luminance levels as described in #I diameter, were placed on the scalp to measure above. The other half of the visual field the VEP responses. Since individuals with (i.e., the hemianopic field) was presented stroke frequently exhibit fixational impairment with a blank, non-patterned stimulus necessitating corrective saccades that may create field (luminance 1.27 cd/m2), as used in artifacts in the recordings, the DIOPSYS software our earlier study.11 incorporates an automated artifact detector. If more than 5 artifacts are detected during a trial, III. Hemianopic field only (HC/HL, LC/ this record is excluded from the analysis. While HL, LL/HC) – In this condition, the only one check size was used (i.e., 20 min arc), checkerboard pattern was presented only

33 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 way, repeated-measures ANOVA was performed for each condition using GraphPad Prism 5.04 software. Graphical displays were also prepared with the same software. Conventional clinical perimetric findings (Humphrey 24-2) were available from the medical records, except for subject S1 (Figure 2). VEP repeatability was assessed in subject S5. The same test conditions were repeated one week later. The coefficient of variation (CV = standard deviation of the multiple sessions for each condition divided by the mean of these multiple sessions for each condition) was calculated to assess for repeatability of the VEP responses.11,17-19 The CV value can range from 0.00 to 1.00.19 This value represents the intra- subject, inter-session variability; the smaller the value, the less the variability, and the better the repeatability.

Figure 2: Conventional visual fields of subjects S2-S5 using Results the central Humphrey 24-2 threshold test (Humphery Visual System, CARL ZEISS MEDITECH). Group Data Amplitude Figure 3A presents the group mean to the hemianopic field (8.5H X 7.5V VEP amplitude for the central, intact, and degrees) with the contrast and luminance hemianopic visual fields for the following three levels as mentioned above in #I. The other stimulus combinations: high contrast (HC) and half of the visual-field (i.e., intact) was high luminance (HL), low contrast (LC) and high presented with a blank, non-patterned luminance (HL), and low luminance (LL) and stimulus field (luminance 1.27 cd/m2), as high contrast (HC). A one-way ANOVA for the used in our earlier study.11 factor of visual field at HC/HL was significant [F (2, 12) = 10.18, p < 0.05]. The post-hoc Tukey Data Analysis test results revealed that the amplitudes for the An average of the three trials for each of the central and intact hemifields were significantly three visual field test conditions (i.e., complete, larger than for the hemianopic field (p < 0.05). intact, and hemianopic), and three stimulus A one-way ANOVA for the factor of visual field combinations (i.e., HC/HL, LC/HL, LL/HC), was at LC/HL was significant [F (2, 9) = 5.88, p < initially calculated for each subject. Then, 0.05]. The post-hoc Tukey test results revealed for each subject, the trial for which the VEP that the amplitude for the central field was response exceeded 1 SD from the mean was significantly larger than for the hemianopic field. deleted to remove this outlier; and, in the case A one-way ANOVA for the factor of visual field where all 3 trial values were within 1 SD, the at LL/HC was significant [F (2, 12) = 10.18, p < most deviant trial response value was deleted. 0.05]. The post-hoc Tukey test results revealed The mean and SD for the 2 remaining trials that the amplitudes for the central and intact were calculated and used for analysis of the hemifields were significantly larger than for the group mean VEP amplitude and latency. A one- hemianopic field (p < 0.05).

34 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Figure 3: Group mean VEP responses for the central, intact, and hemianopic visual fields for the following three stimulus combinations: high contrast (HC) and high luminance (HL), low contrast (LC) and high luminance (HL), and low luminance (LL) and high contrast (HC). Plotted is the mean +1SEM. (A) Amplitude (microvolts) (B) Latency (ms). Brackets indicate statistically significant comparisons (p < 0.05).

Figure 4: Repeatability assessment. Mean VEP responses of subject S5 for session 1 and 2 for the central, intact, and hemianopic visual fields for the following three stimulus combinations: high contrast (HC) and high luminance (HL), low contrast (LC) and high luminance (HL), and low luminance (LL) and high contrast (HC). Plotted is the mean +1SD. (A) Amplitude (microvolts) (B) Latency (ms).

Latency Individual Data Figure 3B presents the group mean VEP The same analyses were performed indiv­ latency (P 100 ms) for the central, intact, and idually on the VEP amplitude and latency data hemianopic visual fields for the following three in each subject. Similar significant results were stimulus combinations: HC/HL, LC/HL, and LL/ found in each subject. See Figures 4A and 4B HC. A one-way ANOVA for the factor of visual for results in a representative subject. Sample field for each of the three stimulus combinations VEP waveforms for one subject for the 3 test was not significant (p > 0.05). conditions (i.e., central field, intact hemifield,

35 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 in stroke patients.11,16 Yadav et al.11 simulated circular, annular, hemi-field, and quadrant absolute visual-field defects in the visually- normal population. They were able to detect and assess reliably all of the aforementioned visual field defect types objectively using the pattern VEP approach. Furthermore, they predicted that the clinical VEP technique would be able to detect and assess actual hemifield defects in clinical patients with stroke, which the present pilot study confirmed. The present findings were also in agreement with Angelelli et al.16 They too were able to detect hemianopic defects in stroke patients using the VEP technique. Moreover, the present study provided additional evidence that visual field loss in stroke patients could be reliably detected as early as the primary visual cortex (V1), in agreement with Angelelli et al.16 Lastly, the objective VEP results typically corroborated the subjective clinical perimetric findings. The present investigation demonstrated for Figure 5: VEP waveforms for a hemianopic subject: (A) the first time that more subtle stimuli, such central field, (B) intact hemi-field, and (C) hemianopic as the LC/HL and LL/HC patterns, may be field. The amplitude values were 8.64, 7.94, and 1.41µ V, respectively. The “plus sign” represents the cursor for N75, particularly useful and highly sensitive in the and the other “plus sign” represents the cursor for P100. detection of hemifield loss in stroke patients. Both the group and individual results revealed and hemianopic field) are presented in Figure that all three stimulus combinations (i.e., HC/HL, 5 A-C. LC/HL, LL/HC) were able to detect hemifield loss in the present small sample of individuals with Repeatability stroke. However, the HC/HL and LL/HC stimulus Repeatability results for subject S5 are combinations provided more reliable amplitude presented in Figure 4A and 4B for amplitude and results, which were consistent with the clinical latency, respectively. Repeatability was assessed visual field findings, as compared to the LC/ after a period of 1 week. The CV (median, range) HL combination (see Figure 3A). Therefore, across the three visual field and three stimulus these two stimulus configurations may be most combinations were: amplitude (median = 0.05, clinically beneficial in detecting and assessing range = 0.02 to 0.80) and latency (median = visual field loss in patients with stroke, especially 0.01, range = 0.0002 to 0.019), thus suggesting in those with clinically variable visual field test good repeatability. findings and/or cognitive dysfunction.

Discussion Clinical Implications The findings of the present study confirmed­­­ The pattern VEP technique should prove and extended the results of previous studies beneficial in individuals with stroke. This demonstrating that the VEP technique could be technique could be used as an adjunct to used to detect for the presence of hemianopia conventional clinical visual field testing to

36 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 detect, assess, and confirm the presence of Study Limitations hemianopia. Due to its objective, rapid, and There were three possible study limitations.­­ repeatable nature, the VEP should be especially First, sample size was small. However, the effect useful in non-verbal and cognitively-impaired was robust. Second, only individuals with stroke individuals with stroke, as they may not be able at the chronic stage were included, but none to understand the instructions and/or respond in either the acute or sub-acute stages were reliably to subjective clinical visual-field testing. tested. In these earlier stages, any cognitive and/ Therefore, the VEP may be an ideal technique or attentional deficits may be more marked, and to detect hemianopic field defects in these hence objective testing may prove to be even patients, as it does not require any verbal (e.g., more beneficial. Third, individuals with visual “yes or no”) or physical (e.g., depressing a neglect were not assessed. button) response by the patient. The VEP could also be used to assess the effect of any visual Future Directions intervention (e.g., eye movement visual scanning There are four possible future directions training) provided to these stroke patients, as proposed. First, a similar study should be has been demonstrated in mild traumatic brain performed with a larger sample size, such as 30 injury (mTBI).20,21 In addition, the VEP could also or more. In addition, hemianopic stroke patients be extended to the traumatic brain injury (TBI) should be included, with and without visual and pediatric populations exhibiting visual-field neglect. The VEP might differentiate objectively defects. Thus, it has the potential to become between those hemianopes with versus without another “tool” in the clinician’s diagnostic the visual neglect aspect, or just for detection and therapeutic armamentarium for a possible of visual neglect alone. Second, as mentioned range of visual field abnormalities across a above, stroke patients at the acute and sub- range of abnormal, neurologically-based, visual acute stages should also be tested to generalize conditions. and extend the present pilot findings. Third, smaller visual-field defects (e.g., quadranopsia) Proposed VEP Hemianopic should be addressed with the VEP technique11 Visual-Field Test Protocol and proposed protocol. Lastly, the effect of any Based on the results of the present study visual intervention (e.g., eye movement training) and another conducted in our laboratory,11 the provided to these patients should be assessed to following abbreviated clinical VEP visual-field demonstrate possible improvement objectively test protocol is proposed in patients with stroke at the early cortical level.20,21 and hemianopia: I. Central field (HC/HL) Conclusion The clinical pattern VEP technique was II. Intact hemi-field only (HC/HL) found to be useful in detecting and assessing III. Hemianopic field only (HC/HL) hemianopic field defects in patients with stroke in the present pilot study. These quantitative Number of trials – 3 trials (each 20 seconds) visual-field findings were found to be repeatable should be performed for each test condition, the and reliable. In addition, these objective findings outlier should be deleted, and remaining two were typically in agreement with the patient’s values averaged. Either, additional trials (e.g., 5) clinical perimetric results. Therefore, the pattern or longer test duration (e.g., 45 seconds)18 could VEP has the potential to be a useful adjunct be performed, if needed, for more consistent technique to test for the presence of visual-field and less variable responsivity. defects in stroke patients.

37 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Acknowledgements 13. Viggiano MP, Spinelli D, Mecacci L. Pattern reversal visual This study was funded by the SUNY/ evoked potentials in patients with hemineglect syndrome. Brain Cogn 1995;27:17-35. Optometry graduate program. We thank 14. Kaizer F, Korner-Bitensky N, Mayo N. Response time of stroke DIOPSYS Inc., Pine Brook, New Jersey, USA, for patients to a visual stimulus. Stroke 1988;19:335-339. providing the VEP system. 15. Spinelli D, Burr DC, Morrone C. Spatial neglect is associated with increased latencies of visual evoked potentials. Vis References Neurosci 1994;11:909-918. 16. Angelelli P, De Luca M, Spinelli D. Early visual processing 1. Feigin VL. Stroke epidemiology in the developing world. in neglect patients: A study with steady-state VEPs. Lancet 2005;365:2160–2161. Neuropsychologia 1996;34:1151-1157. 2. Donnan GA, Fisher M, Macleod M et al. Stroke. Lancet 17. Willeford KT, Ciuffreda KJ, Yadav NK et al. Objective 2008;371:1612–1623. assessment of the human visual attentional state. Doc 3. Goldstein LB, Bushnell CD, Adams RJ et al.; American Heart Ophthalmol 2013;126:29-44. Association Stroke Council; Council on Cardiovascular 18. Willeford KT, Ciuffreda KJ, Yadav NK. Effect of test duration Nursing; Council on Epidemiology and Prevention; Council on the visual-evoked potential (VEP) and alpha-wave for High Blood Pressure Research; Council on Peripheral responses. Doc Ophthalmol 2013;126:105-115. Vascular Disease, and Interdisciplinary Council on Quality of Care and Outcomes Research. Guidelines for the primary 19. Abdi H. Coefficient of variation. In: Salkind N ed. Encyclopedia prevention of stroke: guidelines for healthcare profession of Research Design. Thousand Oaks, CA: Sage; 2010:1-5. from the American Heart Association/American Stroke 20. Freed S, Hellerstein LF. Visual electrodiagnostic findings in Association. Stroke 2011;42:517-584 mild traumatic brain injury. Brain Inj 1997;11:25-36. 4. Hibbard MR, Gordon WA, Kenner B. The neuro­psychological 21. Yadav NK, Thiagarajan P, Ciuffreda KJ. Effect of oculomotor evaluation: a pathway to understanding the sequelae vision rehabilitation on the visual-evoked potential and of brain injury. In: Suchoff IB, Ciuffreda KJ, Kapoor N eds visual attention in mild traumatic brain injury. Brain Inj Visual and Vestibular Consequences of Acquired Brain Injury. 2014;28:922-929. Santa Ana, CA: Optometric Extension Program Foundation; 2001:32-45. 5. Kapoor N, Ciuffreda KJ. Vision disturbances following traumatic brain injury. Curr Treat Options Neurol 2002;4:271- 280. 6. Suchoff IB, Ciuffreda KJ, Kapoor N. (eds.) Visual and Vestibular Consequences of Acquired Brain Injury. Santa Ana, CA: Optometric Extension Program Foundation; 2001. 7. Suter PS, Harvey LH. (eds.) Vision Rehabilitation. Multidisciplinary Care of the Patient Following Brain Injury. New York, NY: Taylor and Francis Group; 2011. 8. Ciuffreda KJ, Ludlam DP. Egocentric localization: Normal and abnormal aspects. In: Suter PS, Harvey LH eds. Vision COVD wishes to thank the following for their Rehabilitation. Multidisciplinary Care of the Patient Following continued sponsorship of special events during Brain Injury. New York, NY: Taylor and Francis Group; the COVD 45th Annual Meeting: 2011:193-211. Good-Lite 9. Reding MJ, Potes E. Rehabilitation outcome following initial Hospitality Suite unilateral hemispheric stroke: life table analysis approach. Stroke 1988;19:1354–1358. HOYA Vision Care 10. Bradnam MS, Montgomery AMI, Evans AL et al. Objective Student Mixer • Virtual Event Bag detection of hemifield and quadrantic field defects by visual evoked cortical potentials. Br J Ophthalmol 1996;80:297- HTS, Inc. 303. Wednesday Evening Open Reception 11. Yadav NK, Ludlam DP, Ciuffreda KJ. Effect of different Thursday Evening Membership Social stimulus configuration on the visual evoked potential (VEP). Miraflex Doc Ophthalmol 2012;124:177-196. Meeting Badges & Holders 12. Odom JV, Bach M, Brigell M et al. ISCEV standard for clinical Thursday Morning Attendee Breakfast visual evoked potentials (2009) update. Doc Ophthalmol 2010;120:111-119.

38 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Article: Retinoblastoma; a Scientific and Clinical Review Thomas Kollodge, BS Biomedical Science, Doctor of Optometry Candidate, Expected 05/15 Sarah Hinkley, OD, FCOVD Associate Professor, Michigan College of Optometry at Ferris State University Chief of Vision Rehabilitation Services Professor, University Eye Center, Big Rapids, Michigan

abstract Introduction: Retinoblastoma is a devas­tating autosomal dominant genetic disease usually seen in children. It causes tumors of the retina which can lead to severe visual impairments and in some cases death.

Body: A defective or absent pRB protein, from a mutated or deleted RB1 gene, causes genomic instability and allows retinoblasts to undergo rapid mitosis. This can lead to the formation of tumors within the retina. As retinoblastoma usually affects infants and young children, they may not notice any changes in their vision or ocular discomfort. The most commonly observed sign of retinoblastoma is leukocoria, caused by the light colored tumor within the eye. There are many treatment options available, some of which include chemotherapy, enucleation, external beam radiation, and radioactive plaques. If caught early, the prognosis is usually very good in the United States. Unfortunately, in second and third world countries the outlook can be significantly worse.

Discussion: Retinoblastoma is a complex disease which can have severe health impacts and endanger the life of the afflicted child. Although this disease is rare, it is the most common primary ocular malignancy in children. Correspondence regarding this article should be emailed Retinoblastoma is caused by a disruption to Thomas Kollodge at [email protected] or call of the RB1 gene. Research has led to the 763-222-7832 . All statements­ are the author’s personal triple hit hypothesis that three mutations are opinion and may not reflect the opinions of the College of required for retinoblastoma formation. Tumors Optometrists in Vision Development, Vision Development & Rehabilitation or any institution or organization to often appear early as translucent thickenings which the author may be affiliated . Permission to use of the retina and evolve into dome-shaped, reprints of this article must be obtained from the editor . white, vascularized masses. The most common Copyright 2015 College of Optometrists in Vision treatments include chemotherapy, radiation Development . VDR is indexed in the Directory of Open and enucleation.­ Early detection is best Access Journals . Online access is available at covd.org . https://doi.org/10.31707/VDR2015.1.1.p39. accom­plished when young children receive comprehensive eye examinations. Catching Kollodge T, Hinkley S. Retinoblastoma; a scientific and the disease before it metastasizes greatly clinical review. Vision Dev & Rehab 2015;1(1):39-45 improves a child’s chance of survival. Early diagnosis and subsequent treatment could Keywords: Retinoblastoma, RB1, pRB, ultimately save a child’s vision or even his or malignancy, tumor, cancer her life.

39 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Introduction Genetics & Pathogenesis Retinoblastoma is the most common primary The tumor suppressor gene associated with intraocular malignancy in children, and can retinoblastoma, RB1, is located on 13q14.2, have devastating effects on a child’s vision and meaning that is found on the q (long) arm health.1,2 It is an autosomal dominant cancer of of chromosome 13, in band number 14, and the retina which typically develops in children within sub band 2.1,3,5 The RB1 gene codes under the age of five or six.1,3 In the case of for the protein pRB, a nuclear protein, which retinoblastoma, autosomal dominance does not is important for regulating cellular growth.4,8 guarantee that the affected person will develop The pRB protein normally binds to the E2F retinoblastoma; it only indicates an increased transcription factor complex, inactivating it, risk.3 It is caused by mutations or deletions of and thus prevents the movement of the cell the RB1 gene, located on chromosome 13.3,4 from the G1 phase to the S phase of mitosis. Retinoblastoma is typically unilateral with Recent studies also suggest that pRB has roles a hallmark sign of leukocoria, noted in the in controlling cellular differentiation, regulating affected eye.1,3 If caught early, especially before apoptosis, sustaining cell cycle arrest, and it metastasizes, the prognosis for patients can chromatin remodling.8 The inactivation of the be very good, but if not, the patient’s life may RB1 gene is also seen in some other forms of be at risk. This review is intended to inform the second cancers.3 Typically, retinoblastoma is reader of the scientific and clinical aspects of caused by a biallelic loss of function or deletion retinoblastoma. of RB1 leading to genomic instability.3,4 Studies have demonstrated that at minimum a third Epidemiology mutation in a separate gene is required, beyond Retinoblastoma affects approximately 1 the biallelic mutations of the RB1 gene, in order in 15,000 to 20,000 people.1,2,3 In the United for retinoblastoma tumors to form. This third hit States, 250-350 children are diagnosed with can occur in another a tumor suppressor gene retinoblastoma each year.5 It is responsible for or oncogene, such as MYCN (2p24.3), E2F3 and approximately 11% of all cancers during the DEK (6p22), CDH11 (16q21), or p75NTR (17q21) first year of life, and 4% of cancers during the and potentially allow for the transformation of first 15 years of life.5,6 After 6 years of age, its retinomas to malignant retinoblastoma tumors.4 incidence is extremely low, peaking during the The genomic instability from the defect in RB1 first few months of life. It is normally diagnosed can also lead to problems in other genes, such around 12 months of age in children who have as the ones listed above. Affecting other genes bilateral retinoblastoma, compared to 24 months can help enable tumor growth within the eye for children with unilateral cases.1 The survival and other tissues throughout the body. rate in the United States is very high, nearing The vast majority of the human genome 100%.2,7 Unfortunately, the prognosis in second is identical from person-to-person. However, and third world countries is not nearly as good, differences exist in the parts of deoxyribonucleic­ which is likely associated with lack of detection acid (DNA) encoding for genes. The differences and poor access to medical care. The survival in DNA bases are known as single nucleotide rate is 81% in China, 48% in India, and as low polymorphisms (SNPs). Human somatic cells are as 20-46% in Africa. Worldwide, it is estimated normally diploid, meaning that they have two that 3,000-4,000 deaths occur annually due to copies of each chromosome. SNPs permit cells retinoblastoma.2 There is no known racial or to have different nucleotide bases within each gender predilection.1,7 chromosome allowing for heterozygosity, or having different copies of genes, as opposed to being homozygous. Deletion or inactivation

40 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 of the RB1 gene, as seen in the case of are unilateral, with the remaining 30-40% being retinoblastoma, is termed loss of heterozygosity bilateral.1 (LOH), since there is only one functional RB1 gene remaining.4 People who have LOH are at a Signs & Symptoms much higher risk for developing retinoblastoma The hallmark sign of retinoblastoma is as it may only take one mutation to occur in leukocoria, defined as a white reflex in the the remaining RB1 gene within a retinoblast to pupil.1,3 This is caused by the reflection of light begin the formation of a retinoblastoma. off the yellow-white colored retinoblastoma Alfred Knundson proposed the two-hit tumor.1,10 The second most common sign theory of retinoblastoma carcinogenesis in of retinoblastoma is strabismus, which can 1971. His theory states that a cell needs to manifest as either exotropia or esotropia.1,3 have two damaged alleles in order for a tumor Strabismus is most likely caused by macular to form. There are two forms of retinoblastoma compromise so proper binocular fixation cannot based off of this model, inherited (familial) or be maintained in the affected eye. Other ocular sporadic. The first hit, or mutation, of inherited signs of retinoblastoma include red eye, excessive retinoblastoma is acquired from the germ cell tearing, buphthalmos, and corneal clouding.1 of a parent. Thus, all the cells of the child Iris discoloration from neovascularization, loss would have one normal and one altered RB1 of fundus reflection secondary to intraocular gene. Due to this LOH, the developing fetus bleeding of the tumor, clumping of white requires only a single mutational event in one tumor cells on the iris or in the aqueous humor, of its retinoblasts in order to initiate a tumor.9 hyphema, glaucoma, and sterile orbital cellulitis As these individuals have a defective RB1 gene may also be observed.1,3 Symptoms may consist throughout all of their cells, they are also of ocular pain, redness, irritation, and decreased more prone to other second cancers such as visual acuity.5 Young children are most often osteosarcoma, melanoma, and various soft affected by retinoblastoma and may be less tissue cancers, depending on which gene(s) the likely to notice or report any ocular discomfort third or any additional hits affect.3,5 Although or blurred vision. very rare, trilateral retinoblastoma can occur Figure 1 shows a photograph of typical when there is a pinealblastoma associated large retinoblastoma. Tumors associated with with bilateral ocular retinoblastoma.1,3 This is retinoblastoma vary greatly in appearance. thought to occur because certain retinal and Discrete intraretinal tumors appear as white, pineal gland tissues are similar.3 The trilateral dome shaped masses with blood vessels growing form has a much higher mortality rate, towards them. Small tumors often appear as accounting for over half of all retinoblastoma translucent thickenings of the retina.1 Exophytic deaths during the first decade of life.7 (growing outward towards the retinal pigment Sporadic retinoblastoma is when the germ epithelium) retinoblastoma tumors are typically cell from each parent has a normal, functional larger, and are associated with rhegmatogenous RB1 gene, but two somatic mutations occur retinal detachments.1,10 On the other hand, in the RB1 genes during fetal development, endophytic (growing towards the vitreous) also known as Knudson’s two-hit theory. A tumors are usually smaller, and their cells may distinguishing factor between the two is that accumulate in the vitreous.1 Occasionally, inherited retinoblastoma is frequently bilateral some tumors may have a mixed endophytic- as all cells are more prone to acquiring the 2nd exophytic growth pattern. Diffuse infiltrating hit needed to form retinoblastoma, whereas retinoblastoma is a rare form which occurs the sporadic variety is usually unilateral.9 when the tumor grows horizontally within the Approximately 60-70% of retinoblastoma cases retina, as opposed to growing vertically as seen 41 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 imaging is the best method of examining the patient’s sellar and parasellar regions of the brain to check for trilateral retinoblastoma. It is also useful for studying the soft tissues of the orbit and optic nerve to check for extraocular spread of a tumor. Fluorescein angiography is typically not used as a diagnostic tool, but if it is performed on a discrete intraretinal retinoblastoma, the angiogram would reveal fast filling of the feeder artery, swift filling of the intralesional vessels, and then quick draining by the efferent vein.1

Management The most important treatment goal of Figure 1: A photograph showing a large retinoblastoma in the posterior pole. Picture courtesy of Aerts et al. Retino­ retinoblastoma is to save the child’s life. The blastoma. Orphanet Journal of Rare Diseases 2006 1:31. next step is to save as much of the child’s vision as possible. If detected early the prognosis is in endophytic and exophytic growth patterns. It usually very good. If left untreated, children often appears as a thickening of the retina and usually die within 2-4 years from the onset of may be mistaken for uveitis, endophthalmitis, symptoms.1 or vitreous hemorrhage.10 Endophytic and Various methods are used to classify infiltrating retinoblastoma tumors are associated retinoblastoma. Historically, the Reese-Ellsworth with vitreous seeding.1,10 Vitreous seeding occurs staging system was utilized. This system divided when tumor cells break off and float freely in retinoblastoma into 5 groups depending on the the vitreous.11 Seeding can make treatment size, location, and number of tumors. It was much more challenging because in addition to used to predict the outcome of eyes treated targeting the main tumor in the retina, each with external beam radiation. Mainly due to the cluster of cells in the vitreous must be targeted. increased use of chemotherapy for treatment, These clusters can deposit elsewhere on the the most common staging system currently retina and start additional tumors.11 Vitrectomy utilized is the International Classification for has not been shown to be an effective treatment Intraocular Retinoblastoma. It divides intraocular for untreated retinoblastoma with vitreous retinoblastomas­ into 5 groups, A through E, seeding and is generally not recommended, with A describing the eye that is likely to be as the openings made in the globe to perform preserved and E describing an eye which is very a vitrectomy may help enable tumor cells to unlikely to be preserved. This system places a spread into the orbit.12 greater emphasis on the presence of vitreous seeding and less on tumor size and location Diagnosis compared to the Reese-Ellsworth system.13 Table There are a variety of methods used to help 1 describes the International Classification for diagnose retinoblastoma. The tumors can be Intraocular Retinoblastoma system. imaged well by ultrasonography, as most large The treatment modalities used for retino­ tumors have intralesional calcification making blastoma depend on numerous factors, including them highly reflective. Also due to calcification, size and location of the tumor, whether it is retinoblastoma tumors can be imaged via bilateral or unilateral, vision/potential vision in computed tomography. Magnetic resonance the affected eye, associated problems from the

42 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Table 1: cells to exit the eye. External beam radiation is International Intraocular Retinoblastoma Classification a very effective method of causing regression in Group A – Very Low Risk Tumors 3 mm or smaller vascularized retinal tumors, but with the advent Eyes with small discrete tumors not threatening vision of chemotherapy it is not used as often as it was in the past.1 This is due to the fact that it can Group B – Low Risk • Tumor greater than induce cataract formation, cause orbital bone Eyes with no vitreous or 3 mm in size growth arrest and consequent facial deformities subretinal seeding • Tumor within 3 mm in children under the age of one, and the tumor of the foveola 1,11 Plaque radiation therapy is • Tumor within 1.5 mm could still recur. of the optic disc another option for retinoblastoma treatment. • Subretinal fluid less This describes a radioactive device (plaque) that within 3 mm of the is placed on the sclera overlying the intraocular base of the tumor tumor, and then removed after a certain Group C – Moderate Risk Vitreous or subretinal period of time, to provide a specific amount Eyes with focal vitreous seeding within 3mm 1 or subretinal seeding of of the tumor of radiation. This method is limited to more any size or location localized retinoblastomas, since the treatment 11 Group D – High Risk Vitreous or subretinal is very confined to the area near the plaque. Eyes with diffuse vitreous seeding greater than 3 Laser photocoagulation and thermotherapy or subretinal seeding mm from the tumor are typically used to treat small tumors, or in Group E – Extremely High Risk • Tumor occupying conjunction with other treatment options.1,2,14 Eyes destroyed by the over 50% of globe Observation without treatment can be performed tumor with one or more • Neovascular glaucoma of the following: • Opaque media in select situations, such as if if the tumor from hemorrhage spontaneously arrests and become dormant.1 in the anterior Pre-malignant retinoblastoma tumors, known chamber, vitreous, or subretinal space as retinomas, should also be carefully monitored­ • Invasion of postlaminar throughout the patient’s life so that any signs optic nerve, choroid, of activation can be detected quickly.1,3 Signs of sclera, orbit, or activation may include morphing in the size or anterior chamber shape of the tumor. The description for the various stages of retinoblastoma from the Fortunately, the survival rate for retino­ International Intraocular Retinoblastoma Classification system.13 blastoma in the United States is very high at around 96.5%.7 Treatment is often a tumor, and the age and systemic health of the multidisciplinary effort between primary eye patient. Systemic chemotherapy is the main care providers and specialists in various fields, treatment performed on children with bilateral such as pediatric oncology, pathology, and retinoblastoma and is often the first treatment radiation oncology.3 Genetic testing may also for unilateral retinoblastoma if the eye may be be recommended to determine whether it was saved.1 It is usually dosed with a combination inherited or a sporadic genetic event. Later in of carboplatin, etoposide, and vincristine.1,11 life, genetic counseling may help the teenager or Chemotherapy is often performed in several adult evaluate the risk of passing retinoblastoma rounds over weeks to months.1 Enucleation may on to his or her children. be performed in advanced cases, usually when the eye is not able to be preserved, such as in Differential Diagnoses grade E retinoblastoma. During enucleation, a There are many possible differential diag­ minimum of 5mm of the optic nerve should be noses for retinoblastoma based on the clinical removed since it is the main route for tumor signs. The most common disorder mistaken

43 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 for retinoblastoma is Coat’s disease, which may also present with leukocoria in children, can also present with leukocoria.1 Coat’s but regardless of the cause, leukocoria warrants disease is a condition in which faulty blood a swift, complete, dilated eye examination. vessels leak in the retina allowing lipids to With early detection, a child’s prognosis for accumulate, forming lesions similar to that of survival is usually very good. Many treatment retinoblastoma. Other differentials of leukocoria modalities are available, and numerous factors include persistent hyperplastic primary vitreous, need to be taken into consideration when ocular toxocariasis, cicatri­cial retinopathy of choosing an appropriate treatment plan. prematurity, familial exudative vitreoretinopathy, Fortunately, the survival rate in the United incontinentia pigmenti retinopathy, and Norrie’s States is very high. Pediatric eye exams need to disease. Intermediate uveitis, microbial endo­ be stressed so diseases such as retinoblastoma phthal­mitis or retinitis, and leukemic infiltra­ and other conditions can be identified early. The tion are all possible differential diagnoses of InfantSEE® program, created by the American vitreous seeds. Some differential diagnoses of Optometric Association (AOA), is an excellent discrete retinal tumors include astrocytoma of start to educating the public on the importance retina, medulloepithelioma, retinal capillary of comprehensive eye exams for infants and hemangioma, and areas of myelinated retinal children. This public health program provides nerve fibers.1 complimentary exams to children between 6 and 12 months of age by a participating Discussion provider. The AOA recommends children Retinoblastoma is the most common without high risk factors to be examined at 6 intraocular malignancy of childhood. It is a months, 3 years, before the first grade, and devastating disease with severe visual impacts every 2 years thereafter.15 Optometrists and and even the possibility of death. Having ophthalmologists play a key role in the detection a basic understanding of the genetics and of retinoblastoma through comprehensive pathophysiology ultimately leads to better care eye exams and collaboration with other for the patient as appropriate referrals can be specialists for its treatment and management. made to specialists for treatment, and to be It is critical that eye care professionals have a examined for second cancers associated with thorough understanding of the clinical signs retinoblastoma. Providers should be able to and symptoms of retinoblastoma, particularly discuss the genetics of the disease, allowing in its early stages. Thorough knowledge of the parents to better understand retinoblastoma genetics and treatment options for the disease and potentially help determine if other family are critical when educating parents stunned by members may be at risk as well. their child’s diagnosis. Since young children do not usually notice problems with their eyes, dilated eye exams References should be performed on a regular basis to catch 1. Augsburger J, Bornfeld N, and Giblin N. “Retinoblastoma.” any problems early. While vision screenings Ophthalmology. By Yanoff M and Duker J. Edinburgh: Mosby Elsevier, 2009. 887-93. Print Edition. may be effective at catching advanced cases 2. Villegas V, Hess D, Wildner A, Gold A, Murray T. of retinoblastoma, screenings lacking red reflex Retinoblastoma. Curr Opin in Ophthalmol. 2013;24(6):581- testing or internal examination and may miss 588. the disease. All children who have an immediate 3. Lohmann, D., and B. Gallie. “Retinoblastoma.” GeneReviews®. family history of retinoblastoma should also have Ed. R. Pagon, M. Adam, H. Ardinger, S. Wallace, A. Amemiya, L. Bean, T. Bird, C. Dolan, C. Fong, R. Smith, and an eye examination shortly after birth, and at K. Stephens. U of Washington. Seattle, National Center for regular intervals thereafter. The trademark sign Biotechnology Information, 18 July 2000. Web. Nov. 2013. of retinoblastoma is leukocoria. Other diseases

44 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 4. Ganguly A, Nichols K, Grant G, Rappaport E, Shields C. 11. Kaneko A, Suzuki S. Eye-Preservation Treatment of Molecular Karyotype of Sporadic Unilateral Retinoblastoma Retinoblastoma with Vitreous Seeding. Jpn J Clin Oncol. Tumors. Retina. 2009; 29(7):1002-1012. 2003;33(12):601-607. 5. “Retinoblastoma.” Genetics Home Reference. U.S. Library 12. Shields C, Honavar S, Shields J, Demirci H, Meadows A. of Medicine, Apr. 2009. Web. Nov. 2013. . Ophthalmology. 2000; 107:2250–2255. 6. Ries L, Smith M, Gurney J, et al (Eds). Cancer Incidence and 13. Shields C, Mashayekhi A, Au A, Czyz C, Leahey A, Survival among Children and Adolescents: United States Meadows A, Shields J. The International Classification SEER Program 1975-1995, National Cancer Institute, SEER of Retinoblastoma predicts chemoreduction success. Program. NIH Pub. No. 99-4649. Bethesda, MD, 1999. Ophthalmology. 2006 Dec;113(12):2276-80. 7. Broaddus E, Topham A, Singh A. Survival with 14. Rodriguez-Galindo C, Orbach D, VanderVeen D. retinoblastoma in the USA: 1975-2004. Br J Ophthalmol Retinoblastoma. Pediatr Clin North Am. 2015 2009; 93:24. Feb;62(1):201-23. 8. Khidr L, Chen P. RB, the conductor that orchestrates 15. Scheiman, M., C. Amos, E. Ciner, W. Marsh-Tootle, B. Moore, life, death and differentiation. Oncogene. 2006 Aug and M. Rouse. “Pediatric Eye and Vision Examination.” Ed. 28;25(38):5210-9. J. Townsend, J. Amos, K. Beebe, J. Cavalleron, J. Lahr, H. 9. Jorde L, Carey J, and Bamshad M. Medical Genetics. McAlister, S. Miller, and R. Wallingford. Optometric Clinical Philadelphia: Mosby/Elsevier, 2010. Print Edition. Practice Guideline. St. Louis, MO: American Optometric Association, 2002. 10. Shields C, Ghassemi F, Tuncer S, et al. Clinical spectrum of diffuse infiltrating retinoblastoma in 34 consecutive eyes. Ophthalmology 2008;115:2253.

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45 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Article: Confus ion Inside Panum’s Area and Symptomatic Convergence Insufficiency Paul Lederer, OD Dmitri Poltavski, PhD, University of North Dakota, Grand Forks, North Dakota David Biberdorf, OD

abstract In the present study we compared the ability of commonly used diagnostic criteria for CI to discriminate between symptomatic pediatric patients and normal controls with corresponding sensitivity and specificity parameters of a novel test of Near Point of Fixation Disparity (NPFD) and a measure of Associated Positive Fusional Convergence (APFC). The results yielded 95% sensitivity and 100% specificity for the NPFD-based criteria, while common Near Point of Convergence and Positive Fusional Convergence criteria were no better than chance. Supplemental use of NPFD and APFC are expected to increase the sensitivity of optometric evaluation to CI without compromising its specificity.

Convergence Insufficiency (CI) is a bino­cular positive fusional convergence (PFC) at near.2 vision disorder that represents a specific type of It is often associated with symptoms such as decompensated hetero­phoria. Evans1 classified double vision, eyestrain, headaches, blurred the symptoms of decompensated heterophoria vision, and loss of place while reading or into three categories: visual symptoms (blur, performing near work. Not all patients with diplopia, distorted vision); binocular difficulties CI, however, present with symptoms possibly and asthenopia. Convergence Insufficiency due to either suppression, avoidance of near is typically characterized by exophoria that is visual tasks, high pain threshold or monocular greater at near than distance, a remote near occlusion.2 Yet symptoms associated with CI point of convergence (NPC) or decreased may negatively affect a person’s quality of life by interfering with school, work, and leisure Correspondence regarding this article should be emailed activities performed at near. The presence of CI to Paul Lederer, OD, at [email protected] . All state­ may contribute to parental reports of difficulty ments are the authors’ personal opinion and may not with their child’s ability to complete schoolwork reflect the opinions of the College of Optometrists in Vision 3 Development, Vision Development & Rehabilitation or any efficiently, whereas a successful or improved institution­ or organization to which the author may be outcome after CI treatment has been shown to affiliated . Permission to use reprints of this article must be associated with a reduction in the frequency be obtained from the editor . Copyright 2015 College of of adverse academic behaviors and parental Optometrists in Vision Development . VDR is indexed in the Directory of Open Access Journals . Online access is available concern associated with reading and school at covd.org . https://doi.org/10.31707/VDR2015.1.1.p46. work as reported by parents4. The diagnostic criteria for CI have been Lederer P, Poltavski D, Biberdorf D. Confusion inside neither consistently applied by investigators and panum’s area and symptomatic convergence insufficiency. clinicians nor have been particularly accurate in Vision Dev & Rehab 2015;1(1):46-60. identification of CI in the presence of asthenopia. For example, Rouse5 reported that 93.8% of Keywords: fixation disparity, NPFD, the optometrist’s surveyed in their study used Convergence Insufficiency reduced NPC for the diagnosis of convergence insufficiency. Others believe that an exophoria 46 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 greater at near must be present, along with defined for a stimulus at a fixed retinal locus either a reduced NPC or PFC. Yet there are as the retinal area, upon which a target can be many who believe that all three criteria need to imaged in the other eye and appears fused.10 be satisfied (both the NPC and PFC should be Disparities that exceed this limit result in diplopia reduced in the presence of an exophoria) before or binocular rivalry. Hence Panum’s area is also a CI can be diagnosed.6 threshold measure of diplopia.11 On the other hand, in some cases, none Within Panum’s area, however, double vision of the 3 criteria may be abnormal, yet CI may is not experienced, and yet a significant binocular be diagnosed in the presence of asthenopia disparity dysfunction can be present and can associated with convergence.2,7,8 Rouse et manifest itself as asthenopia.12 In a review of al.6 further reported that out of 206 children literature on visual discomfort and visual fatigue between 8 and 12 years of age whose records Lambooij and Ijsselsteijn13 contend that under showed none of the 3 classic signs of CI (were natural viewing condi­tions retinal disparities classified as “no CI”), 25% had symptoms within Panum’s fusion area beyond 1° are consistent with Convergence Insufficiency assumed to cause visual discomfort. The authors including the presence of symptoms when equate this 1° area around Donder’s line with reading or writing, such as headache, diplopia, Percival’s zone of comfort defined as the middle eye fatigue, or print running together when third of the amount of binocular vergence reading. Furthermore, because convergence with almost no change in accommodation, i.e., in the pre-presbyopic population is never the middle third of “the zone of clear, single independent of the accommodative system, binocular vision.” due to the interactive negative feedback loop At the same time while NPC and VRR between accommodation and vergence, a measures may not be sensitive to asthenopia- convergence problem may be secondary to inducing vergence issues occurring within a primary accommodative problem, and vice Panum’s fusion area, traditional measures of versa.9 These issues of inconsistency and fixation disparity using dichoptic targets and inaccuracy of CI diagnosis continue to thwart binocular fusion locks are assumed to address attempts to estimate CI prevalence in pediatric retinal disparity within PFA, when the object is and adult populations, impede development of still seen singly.14,12 The angular value of fixation effective treatment strategies and interfere with disparity is a measure of the degree to which evaluation of treatment outcomes. the images have slipped.15 The conventional Another reason for difficulty in establishing view is that fixation disparity typically measures clear diagnostic criteria for convergence insuf­ between 5 and 10 min of arc and rarely exceeds ficiency may be related to the fact that classic 10 min of arc.16 vergence and near point of convergence Yekta and Pickwell17 investigated fixation measures used by clinicians can underestimate disparity in relation to symptomatic convergence binocular dysfunction. The classic Divergence- insufficiency using the Mallett fixation disparity to- Convergence Recovery range (VRR) and Near unit, in which at near the central fixation Point of Convergence (NPC) measures evaluate target OXO is seen with both eyes and the two when the burden of fusion demand placed upon monocular markers (nonius strips) in line with binocular vision becomes too great and diplopia the ‘X’ are seen one with each eye using cross becomes manifest as fusion limits are exceeded polarizing filters. Symptomatic participants had (break point) and when fusion recovers (recovery significantly higher degrees of fixation disparity point). In its turn diplopia occurs when retinal than asymptomatic ones. This finding was fixation disparity falls outside of Panum’s area. consistent with Mallett’s18 and later Sheedy and In 1858 Panum described Panum’s fusional area Saladin’s19 suggestion that fixation disparity is a

47 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 better indicator of decompensated heterophoria from 10 to 65 years. The authors reported a than the degree of heterophoria. Similar findings statistically significant relationship between were reported by Yekta et al.20 and Pickwell et visual symptoms for near and the magnitude al.21 for decompensated heterophoria at near. of fixation disparity and associated phoria for Jenkins et al.22 also reported that the sensitivity all age groups. They did not, however, find any of the Mallett’s test to decompensated relationship between the presence of symptoms heterophoria in pre-presbyopes was 75% with and phoria measurement. Similarly, exo fixation specificity of 78%, if an aligning prism at near disparity (FD) (or the related associated phoria) of 1Δ or greater was used as a cutoff for failing at 40 cm indicated visual symptoms in the the test. studies of Sheedy and Saladin24,19,25 and the of The location of the fusion lock in a clinical Pickwell group.26,22,17,21 Additionally Jaschinski27 target may be an important factor in the also reported that in nonpresbyopic subjects measurement of fixation disparity. Because with normal vision but who differed in near it is important to orient the fusion lock to be vision fatigue at a 50cm viewing distance, most sensitive to such “stressful” near tasks higher fatigue was significantly associated with as reading, it is important to make this central a steeper proximity-FD curve (more exo FD and target contain a letter in order to help draw near vision). one’s attention toward letter identification. The additional use of associated vergence Ciuffreda23 demonstrated that in visually normal measurements in nearpoint binocular assessment individuals, accommodative interactions with will determine how well an individual’s vergence vergence accounted for up to 50% of the response may keep up with a changing measured fixation disparity found under normal vergence demand (prism adaptation time). The viewing conditions. He also found that the use traditional “blur”, “break” and “recovery” of an accommodative target, such as a letter, patient responses created when classic vergence showed less vergence variability as compared to measurements alone are performed may a penlight stimulus. Therefore, attention to the now reveal, under associated measurements, clarity of the accommodative target facilitates when a vergence demand-response mismatch a better evaluation of focal binocular fusion occurs, characterized by misalignment of the as target identification is now more intimately vertical nonius lines. In addition, the larger the involved with its orientation. difference between the classic and associated Similarly with the use of the same central vergence findings, the more these patients can fusion lock, measures of associated vergence encounter visual stress without the presence of can be evaluated by recording reported fixation double vision. disparity that is induced when vergence eye In the present study we evaluated a novel movements lag behind a changing vergence test of near point fixation disparity used in two demand, either by moving the target inward ways: and outward or by creating gradual increases in 1. as a relatively quick and easy assessment convergence (BO prism) or divergence (BI prism), of fixation disparity to an incoming and respectively. These measures of associated outgoing dichoptic target, similar to vergence responses may be more sensitive to NPC, where an exo fixation disparity thresholds of binocular dysfunction than classic was induced as the target approached vergence measures and can thus complement a patient’s nose and a reduction in exo diagnostic criteria for CI. For example Yekta fixation disparity occurred as it receded. et al.20 investigated phoria, associated phoria, This is called the Nearpoint of Fixation fixation disparity and stereopsis for near vision Disparity Test (NPFD) and is a measure in a sample of 187 subjects ranging in age of vergence response to the combined 48 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 changes in proximal, accommodation and span for critical visual activities at near point, fusional vergence demand. intermittent blurring and double vision, loss of 2. As a test, where the NPFD target remained place during sustained near visual tasks and at a fixed nearpoint (40 cm.) distance ocular headaches following sustained near while associated vergence ranges were visual tasks, well as motion sickness. Symptom measured with prism. This is called the reports were obtained from an entrance history Associated Vergence Ranges, which form and from the Doctor’s interview. measures vergence response to changes In their review of Convergence Insufficiency in fusional vergence demand alone, with Cooper and Jamal2 noted that up to 18% of no direct changes in accommodative patients with CI may be asymptomatic because vergence or proximal vergence. of either suppression, avoidance of near visual tasks, high pain threshold, or monocular We compared these measurements made occlusion. For this reason during the selection under associated, dichoptic conditions to special attention was also paid to those patients classic measures of near point of convergence who reported avoiding near work (especially (NPC) and positive fusional convergence at reading) and, therefore, originally did not near (PFC). We then evaluated the sensitivity report any symptoms. For many, symptoms of the diagnostic criteria using traditional NPC were present but revealed through follow- and PFC measures to the symptoms of CI with up questions that were specifically aimed at the corresponding sensitivity of the statistically situations, which required sustained visual derived criteria for NPFD and associated performance. This is well represented by the measures. We hypothesized that the latter standardized testing often experienced in would show much greater sensitivity to CI as school. It is their adaptation to this challenge these measures would not only capture those or conflict to stay in visual focus despite the patients whose symptoms are driven by binocular presence of increasing symptoms, which can be dysfunction measured outside of Panum’s area, insightful regarding their visual history. Other but also those whose binocular deficits could be probing questions relate to their having to read measured as occurring within PFA. out loud as they begin to show an increasing trend toward the misreading or substituting of Methods primarily the small words. The reading out loud Participants of unfamiliar material presents a situation that This was a retrospective study using makes their visual issue public and embarrassing. records of 60 pediatric patients between 6 As a result they develop behavioral adaptations and 17 years of age (M= 10.56, SD=3,61), of avoidance regarding reading out loud and who were seen as part of a normal private often tend to do the minimal amount of near practice in a Midwestern optometric clinic. work (i.e. reading) required. These characteristics Thirty-five of the patients did not report any complicate the process of discovery when symptoms of convergence insufficiency and investigating clinical history. They also reflect the had normal binocular vision, while 25 of them emotional collateral damage that often occurs reported significant asthenopia consistent with as a result of Convergence Insufficiency going symptoms of some binocular disorders including undiagnosed and untreated. When questioning convergence insufficiency. Specific symptoms these patients the first author (Lederer) often included unusual visual fatigue during near- indicated to them that he could attempt to work tasks such as reading, slow and inaccurate get them accommodations that would provide reading and poor comprehension, loss of focus extended time on those tests and asked them and concentration, limited visual attention whether they would use the extended time 49 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 if they had it. Their answer was often “NO”. to increase sensitivity of the NPC-based criteria These types of questions are clinically insightful to symptomatic CI (easier to classify someone as and provide additional clues to the performance having CI). Consistent with other CITT group’s for those who have made avoidance adaptations eligibility criteria for their CI treatment trial, we to their visual dysfunction. These behavioral used a 7cm clinical cutoff for NPC recovery and avoidance characteristics can make the presence a PFC criterion of 15 Δ BO break when estab­ of symptoms more difficult to reveal. In contrast, lishing diagnostic criteria for CI in their study of those who tend to fight against visual stress to school-aged children between 9 and 18. perform well typically reveal symptoms more Diagnostic criteria for fixation disparity and overtly, associated phoria were statistically derived (see Exclusionary criteria included presence of results section below) and included reduced amblyopia, convergence excess, divergence NPFD (≥ 5cm break and ≥ 6cm recovery) and excess exotropia, constant strabismus and reduced associated vergence (< 16 Δ BO break). accommodative insufficiency as defined by a In our study we did not look at exophoria reduction in accommodative amplitude during at near as a predictor of asthenopia as in their monocular minus lens bar amplitude assessment review Cooper and Jamal2 did not consider done at 13” using a .62M acuity target. presence of abnormal exophoria at near a Similarly case histories for the control necessary condition for the diagnosis of common group were selected from the pool of pediatric CI. In research studies presence of exophoria at patients who were not identified as having any near in patients with CI ranges between 63% oculomotor problems, who did not report any 30 and 79%.31 symptoms of asthenopia and typically reported being good readers and liking near work Materials (computer work, reading etc). Patient histories Near Point of Convergence (NPC) were thus assigned to either symptomatic or The near point of convergence (NPC) asymptomatic groups. Furthermore, this was measure has been shown to be a useful tool a single-blind design as the data analyst was in assessing convergence insufficiency.32 The unaware of the association between symptoms fixated target is gradually moved toward the (group membership was coded with either patient until it becomes double. The target is 1 or 2) and test values until all analyses were then moved back until it has become single completed. again. The break and recovery findings are The likelihood of CI was estimated using recorded. The repetition of this test is a useful some of the well-established conservative modification to the single measure and can diagnostic criteria for CI as well as estimates reveal more subtle diagnostic issues regarding of fixation disparity and associated phoria. reduced stamina.32 A variety of targets have The former included presence of both reduced been used such as a penlight, a penlight NPC (break ≥ 5cm and recovery ≥ 7) and PFC with red/green glasses, and an identification (less than 15 Δ BO break). These criteria were target to engage accommodation. Ciuffreda33 based on a number of previous research reports. and later Scheiman et al.32 showed that an Specifically, Maples and Hoenes28 suggested accommodative target showed less variability as that the criterion for the NPC break score to compared to the penlight stimuli. This type of differentiate symptomatic from less symptomatic target (a single 20/30 letter) was used in the elementary school children should be 5 cm or present study. The Bernell Accommodative Rule greater. We chose this cut-off instead of 6 cm (Bernell Corp., Mishawaka, IN) was placed just used by the CITT group with children between above the nose at the brow between the two 9 and 18 years of age (see Scheiman et al.29) eyes of the participant. The target was then

50 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 fusional convergence-PFC). The patient was then instructed to report the recovery of single vision (fusion) as the prism direction was reversed, and the amount of prism was decreased by the examiner. A similar procedure was used with base-in (BI) prisms to determine negative fusional vergence (NFV) at near.

Near Point of Fixation Disparity (NPFD) The NPFD test and its target have been originally developed and tested by the first author of this study (Lederer) . When administering the NPFD, the target represents a fixation disparity cross [Figure 1] that is mounted on a hard Figure 1: Near Point of Fixation Disparity (NPFD) test (reproduced with permission from Vision Assessment board with a silvered background. The circle Corporation). that surrounds the E represents part of the fusion lock. The central E target is equivalent moved toward the participant at a rate of about to a 20/100 sized reduced Snellen letter, which 1 to 2 cm/s. Subjects were encouraged to try to subtends the eye at 25’ of arc. The circle surround keep the target single. The subjective break and is equivalent to a 20/200 sized reduced Snellen recovery values were measured and recorded in letter, which subtends the eye at 50’ of arc. The centimeters. If there was no subjective report E and circle are solid and are seen by both eyes. of diplopia, the points at which the patient The circle’s spherical shape steers attention objectively lost and regained ocular alignment toward its perceptual center, which supports were recorded as the break and recovery. The the judgment involved in aligning the arrows. NPC was measured twice for each subject and The NPFD Card was placed on the moveable average values for break and recovery were then rod of the Bernell Accommodation Rule while used in the analyses. the subject wore polaroid vectograph glasses as a way to dichoptically view nonius lines (right Fusional Vergence at Near eye seeing top the line, left eye seeing the Positive and Negative fusional veregence at bottom line) while both eyes fused the central near were measured using a hand-held Risley E target and circle surround. The center of the prism in free space. With the patient seated and forehead at the level of the brow was used as wearing their refractive correction, he/she was the zero measure point from which the NPFD instructed to view the same accommodative was taken. With the end of the ruler placed target that was used in the NPC (i.e. a single against the forehead, the target was moved 20/30 letter) displayed on a near card and slowly toward the subject at approximately one held before the eyes at a distance of 40 cm. to two centimeters per second until the subject The patient was then instructed to inform the reported that the vertical noinus lines began examiner when the print was seen to blur to move out of alignment, at which point the and/or become double as the examiner slowly distance from the zero measure point was read introduced an increasing amount of base-out off the ruler. The ability to observe offset is very [BO] prism in front of either eye. When/if blur sensitive especially if a patient (even a young was reported, the amount of base-out prims pediatric patient) is instructed to report when was smoothly and continuously increased until the arrows “begin sliding”. The presence of the break-point (double) was reported (positive an unresolved fixation slip, without diplopia,

51 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 represents the associated phoria for that specific present study all testing was done is free space. distance. Disparity break and recovery findings The patient was instructed to maintain clarity were recorded as the break/recovery of the of the central fusion lock “E” during testing NPFD. While viewing the target the patient was and to indicate when an unresolved fixation asked to maintain the fusion lock clear and as disparity became apparent as the convergence the target is moved from a far point distance (BO) or divergence (BI) prism demand was (often started outside 50”) toward the patient gradually increased at a rate of approximately 1 they were to indicate when a fixation disparity second/ 5pd. During this testing the patient was slip developed and could not be resolved in the asked “are they still straight and clear?” This time it took to ask “Is it still sliding?”. Other question was meant to aid arousal and visual diagnostic questions commonly used during discrimination. The prism demand was increased the administration of the NPFD include: “Is it until the patient reported that the arrows were shifting?”; “Is it still off or did it line up again?”; “sliding.” They were then immediately asked “Is it blurring?”; “Is either of the arrows fading “are they STILL sliding?” The time necessary for out?” Once there is a better understanding of recovery is the time it took to ask this question. test parameters that are to be attended to, it When the patient indicated that the arrows then becomes easier to just integrate these were still offset, the prism demand was rapidly questions into: “Is it breaking up?”; “Did it increased another 5pd and then gradually come back together or is it still breaking up?” decreased until the patient recovered both The term “breaking up” represents a disruption alignment and clarity. This information provided to binocular vision that is reflected as a fixation measures of associated BO and BI vergence disparity, or a blurring of the letter “E” fusion break and recovery recorded in prism diopters. lock or suppression. The target was then moved back to the Statistical Analyses distance until the nonius lines appeared to be To determine the best cutoff values for both aligned and clear. While the NPC evaluates break and recovery points on the NPFD test as the distance at which double vision is seen as well as the BO break point for the associated fusion breaks and when single vision is seen as convergence measure we first calculated 25th, fusion recovers, the NPFD evaluates when the 50th, and 75th percentiles for each measure two eyes, prior to separating, begin to “argue” and then used each of the percentile scores to and misalign due to the increased vergence and discriminate between patients with symptoms accommodative demand and then become re- of CI and asymptomatic control patients using a aligned as the vergence and accommodative series of Receiver Operating Characteristic (ROC) demand is gradually reduced and the binocular Curves. ROC curves are graphs of sensitivity of argument is resolved. Although both of the a particular measure to CI symptoms plotted measures involve a significant degree of against the false positive rate of CI diagnosis proximal, accommodative and fusional vergence (1 – specificity). Specificity refers to the measure’s responses, the NPFD yields a more sensitive ability to identify patients, who do not have a perceptual indication of the breakdown of one target characteristic (i.e. CI symptoms). The or more of these mechanisms. ability of two or more variables to diagnose an outcome can be compared using ROC curves Associated Vergence and their associated areas under the curve Associated vergence was measured with the (AUROCs) that the ROC tests also provide. The fixation disparity target as used for NPFD (Figure ideal test would have an AUROC of 1, whereas 1) and rotary Risley prism. This testing can be a random guess would have an AUROC of done in free space or in the phoropter. In the 0.5. According to Hoshmer and Lemeshow’s

52 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Table 1: Receiver Operating Characteristic (ROC) Curves’ Area Under the Curve (AUC), 95% Confidence Intervals (CI) of AUC, Sensitivity and Specificity and the resultant Youden’s index for each traditional and associated test of vergence and CI diagnosis. Measure AUC 95% CI Sensitivity Specificity Youden’s index NPFD break point >50th pcntl (4cm) 0.885* 0.79-0.98 0.91 0.86 0.77 >75th pcntl (14.25cm) 0.804* 0.67-0.94 0.61 1.00 0.61 NPFD recovery point >50th pcntl (5cm) 0.893* 0.80-0.98 0.96 0.83 0.79 >75th pcntl (18.25cm) 0.804* 0.67-0.94 0.61 1.00 0.61 APFC break point (BO) <25th pcntl (3.5 Δ) 0.813* 0.68-0.93 0.63 1.00 0.63 <50th pcntl (16 Δ) 0.971* 0.92-1.00 1.00 0.94 0.94 <75th pcntl (17Δ) 0.714* 0.58-0.84 1.00 0.43 0.43 CI according to NPFD break >4 0.98* 0.92-1.00 0.95 1.00 0.95 cm and NPFD recovery > 5 cm and APFC break BO <16 Δ CI according to NPC break 0.59 0.43-0.75 0.19 1.00 0.19 ≥ 5cm and recovery ≥ 7and PFC BO break < 15 Δ

36 criteria AUCs between 0.7 and 0.8 indicate Finally we directly compared the sensitivity acceptable discrimination, AUCs between 0.8 of traditional CI diagnostic criteria and those and 0.9 show excellent discrimination with utilizing NPFD and APFC values to symptoms of values equal to or above 0.9 reflecting the test’s CI using ROC curves. outstanding discrimination ability. We thus We also conducted a series of independent utilized these guidelines to select the best cutoff sample t-tests comparing traditional and scores for each measure and in cases of similar associated measures between the symptomatic AUCs we further calculated Youden’s index (J) CI and non-symptomatic normal groups and and selected values with the highest J. Youden’s calculated the magnitude of effect size for index is represented by the following formula: each comparison using Hedges’ g.39 This index J = sensitivity + specificity – 1 is similar to Cohen’s d but instead of using the population standard deviation it utilizes pooled According to Bewick, Cheek and Ball37 in standard deviation for the comparison groups. instances where both sensitivity and specificity According to Ferguson40 g values around 0.4 of a diagnostic test are equally important, cutoff indicate a recommended minimum effect size, values with the highest Youden’s index should values around 1.15 are considered moderate, be used. while anything equal to or greater than 2.7 Since the likelihood of CI is traditionally should be considered a ‘strong’ effect. This estimated using conservative diagnostic criteria effect size estimate evaluates the magnitude such as the presence of both reduced NPC of group differences on a particular measure (break ≥ 5cm and recovery ≥ 7) and PFC (<15 and is an indirect index of the likelihood Δ BO break;38,2), we similarly utilized identified that the observed values on a given measure cutoff values for the NPFD and the BO break belong to representatives from two different point of associated convergence to arrive at populations (i.e. CI vs. no CI). So the greater an algorithm for CI diagnosis using the latter is the magnitude of the effect size, the higher measures. is the probability that the observed means describe two different populations.

53 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 a. b.

Figures 2a, 2b, 2c: Receiver Operating Characteristic (ROC) Curves for the 50th and 75th percentiles of the NPFD break (a) and recovery (b) and the 25th, 50th, and 75th percentiles of Associated Vergence BO break (APFC; c) in relation to presence of CI symptoms (sensitivity).

Results ROC Curves Percentile scores for the NPFD break point for the entire sample showed that both the 25th and 50th percentiles were equal to 4 cm while the 75th percentile for the sample was 14.25 cm. ROC curves on these percentile scores discriminating between symptomatic and asymptomatic patients showed that both NPFD break values above 4 cm and 14.25 cm significantly predicted CI symptoms (AUC=0.885 and AUC=0.804, respectively). The Youden’s index, however, was greater for the 50th c. percentile (J=0.77) than for the 75th percentile (J=0.61), thus the value of 4cm was selected as a diagnostic cutoff for the NPFD break with values higher than 4cm indicating probability of and Lemeshow’s36 criteria provided excellent CI. These results are summarized in Table 1 and discrimination (>0.80), scores above the Figure 2a. 50th percentile (5cm) provided much greater Similarly, although both the 50th and the sensitivity to CI (0.96) and a correspondingly 75th percentiles for the NPFD recovery had much higher Youden’s index (J=0.79) compared significant AUCs, which according to Hoshmer to NPFD recovery values above the 75th

54 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 Table 2: Independent-sample t-tests comparing NPC / PFC and NFPD /APFC measures of the CI-symptomatic group (n=25) with corresponding measures of the non-symptomatic normal patient group (n=35). Symptomatic CI No CI Measure 95% confidence Mean (SD) 95% confidence t Hedges’ g Mean (SD) interval for mean interval for mean NPC Break (cm) 6.04 (4.63) 3.56-7.57 3.37 (0.60) 3.16 – 3.57 2.81** 1.02 NPC Recovery (cm) 8.43 (4.94) 5.91-10.19 4.45 (0.74) 4.20-4.71 3.83** 1.40 PFC Break (B0) Δ 14.16 (7.67) 10.08-16.58 21.17 (3.65) 19.91-22.42 -4.15** 1.24 NPFD Break (cm) 20.30 15.21-27.08 3.85 (0.84) 3.57-4.14 6.02** 2.38 (12.99) NPFD Recovery (cm) 23.56 18.87-29.61 5.02 (0.82) 4.75-5.31 7.56** 2.95 (11.74) APFC Break (BO) Δ 0.88 (5.09) -1.81-2.86 16.94 (1.92) 16.28-17.60 -14.75** 4.58 *-significant at alpha=0.05; equal variances are NOT assumed. **-significant at alpha=0.01; equal variances are NOT assumed. (J=0.94) for the 50th percentile (15Δ). The values below the 50th percentile on the APFC were thus used for CI diagnosis (see Table 1 and Figure 2c for details). ROC curves were then generated for the combined probability of CI diagnosis according to NPFD break values greater than 4cm, recovery values greater than 5cm and APFC less than 15Δ BO break and commonly accepted NPC- based criteria (NPC break ≥ 5cm and recovery ≥ 7; and PFC < 15 Δ BO break). The results showed that NPFD-based discrimination among CI-symptomatic and asymptomatic patients was almost perfect (AUC=0.98), while similar NPC-based diagnostic criteria were no better than flipping a coin (AUC=0.56). Furthermore, while both types of criteria reliably identified asymptomatic patients (specificity for both = 1.0), sensitivity to CI symptoms was 0.95 for Figure 3: Receiver Operating Characteristic (ROC) curves for the NPFD-based criteria and only 0.19 for the NPFD with APFC-based diagnosis of CI and NPC with PFC- NPC-based criteria (see table 1 and Figure 3 for based CI diagnosis in relation to the actual presence of CI symptoms (sensitivity). details). Essentially in the present study 81% of symptomatic patients were overlooked by percentile (18.25 cm) and Youden’s index of the standard diagnostic criteria and classified 0.61 (refer to table 1 and Figure 2b for details). as NOT having CI, while NPFD-based criteria The 50th percentile for the NPFD recovery was identified 95% of the symptomatic patients. thus selected as another cut-off criterion in CI Independent group t-tests also supported diagnosis. these findings. Although the CI and non-CI Finally the ROC curves for the 25th, 50th, groups were significantly different on all of and 75th percentiles of associated fusional the traditional and associated measures of convergence (BO break point for associated Convergence Insufficiency, the magnitude of vergence) showed the highest Youden’s index the effect sizes for the associated measures

55 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 was large using Ferguson’s criteria,40 while the The inspection of the group means in corresponding effect sizes for the traditional Table 2, however, explains these findings. measures were moderate (see Table 2 for details). The NPC break for the asymptomatic control This suggests a greater likelihood that on the group was 3.37 cm while the corresponding measures of Near Point of Fixation Disparity and mean for the symptomatic group was 6.04 Associated Positive Fusional convergence any cm. This difference was statistically significant two randomly sampled individuals from CI and (t=2.81, p<0.01). Yet for the NPC break only normal populations are going to be different values lower than 5 cm were considered (greater sensitivity of NPFD and APFC) compared asymptomatic, which created an overlap to the probability of observing such difference with the 95% confidence interval for the with traditional measures of NPC and PFC. symptomatic group mean of 6.04 cm (95%CI= 3.56 cm-7.58cm, see Table 2). Similarly while Discussion the NPC recovery for the control group was Consistent with the original hypotheses the 4.45 cm, which was significantly better than results of the study have shown that receded the corresponding mean for the symptomatic Near Point of Convergence and reduced Positive group (M=8.43), the selection of values below Fusional Convergence amplitude at near in 7cm as indicative of the normal population many cases was not sufficiently sensitive to the was again too liberal for the present sample symptoms of Convergence Insufficiency. The making it fall within the 95%CI for the mean sensitivity of the combined diagnostic criteria of the symptomatic group (5.91cm-10.19cm). for these measures in our study was only 19%, Finally, the mean PFC BO break for the control with 81% of the pediatric CI-patients classified group (M=21.17Δ) was significantly better as having no CI. At the same time diagnostic than for the symptomatic group (M=14.16Δ), criteria based on the NPFD and APFC identified but inclusion of values above 15Δ as the 95% of the patients with CI symptoms and criterion of normal convergence at near was did not misclassify any of the asymptomatic again overly permissive as it fell within the controls with normal binocular function. 95%CI for the mean of the symptomatic group Part of the issue here may have to do (95%CI= 10.08Δ-16.58Δ). with the fact that our cut-off values based on It is thus very likely that in a much larger fixation disparity and associated phoria were sample the variability around the mean for derived directly from the sample measurements, symptomatic and asymptomatic patients is while similar criteria based on the receded NPC going to decrease (greater confidence that and reduced PFC were based on the reported the means reflect true population means), pediatric norms.38,2 For convergence insufficiency which would increase the sensitivity of NPC the NPC is almost always closer to the patient and PFC-based criteria with cutoffs used. It is (inside) than the NPFD measure, as the former also likely that the sensitivity of the NPFD and is supposed to occur outside of PFA while APFC-based measures will decrease somewhat. fixation disparity takes place within PFA12. It is Based on the first author’s clinical practice with thus almost counterintuitive why in the present over 1000 pediatric patients with convergence study the NPFD break point greater than 4cm, insufficiency the diagnostic criteria for CI NPFD recovery point greater than 5 cm and derived from fixation disparity and associated APFC BO break less than 16Δ in combination phoria are somewhat more liberal: NPFD break resulted in a much better diagnostic algorithm >8cm, recovery >12cm and APFC BO break identifying patients with asthenopia than very <16Δ. Applying these criteria to the sample in similar criteria used for NPC (>=5cm break and the present study we were still able to obtain >=7cm recovery) and PFC (<15Δ). 70% sensitivity and 100% specificity (see 56 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 or behavioral avoidance /adaptation to the demands of near work. Overall our finding of greater sensitivity of tests of fixation disparity to symptoms of convergence insufficiency is supported by previous research. Yekta and Pickwell17 reported that symptomatic participants had significantly higher degrees of fixation disparity than asymptomatic ones in their study using the Mallett fixation disparity unit. Jenkins et al.22 also reported that the sensitivity of the Mallett’s test to decompensated heterophoria in pre- presbyopes was 75% with specificity of 78%, if an aligning prism at near of 1Δ or greater was used as a cutoff for failing the test. The Mallet Unit Fixation Disparity Test, how­ ever, measures associated phoria as it does not measure angular fixation disparity but instead measures the prismatic power that eliminates Figure 4: ROC curve for clinically derived diagnostic criteria the fixation disparity. In the present study we for CI with NPFD break > 8 cm, NPFD recovery > 12cm, and did both and used combined statistically derived APFC < 16 Δ. criteria to predict symptoms of convergence insufficiency. On the NPFD test we also used Figure 4 for details). The area under the curve a central fixation disparity lock in the form of for the generated ROC curve was 0.848, which accommodative binocularly viewed ‘E’ target, indicates ‘excellent’ discrimination according to which is intended to maximally simulate the Hoshmer and Lemeshow’s36 criteria. visual demands of reading. The circle or ring, Additionally the observed mean NPC and that surrounds the E, frames the identification PFC values in the symptomatic CI group in target to support the perceptual judgment of the present study did not correspond to what the shape’s center of symmetry. This symmetrical Rouse et al.6 determined to be “definite CI” shape facilitates judging alignment. Attention in a pediatric sample of 620 patients. In their to the clarity of the accommodative target (‘E’) study this CI classification was characterized by facilitates better evaluation of focal binocular the mean NPC break of 11.8 cm (+/-6.0) and fusion. Identification is now intimately involved recovery of 16.9 cm (+-5.7) with corresponding with orientation. This corroborates the theory PVC BO break and recovery values of 12.1Δ (+/- that measurements of vergence that are made 4.3) and 3.7Δ (+/-4.8), respectively. Our CI group when targets exceed or enter the outer limits values (see table 2 for details) on these measures of Panum’s region are not as sensitive as fell somewhere between ‘low’ and ‘high suspect associative vergence measurements that reveal CI’, according to the classification of the Rouse how centralized the dichoptic targets are within et al.6 study. It is, therefore, likely that the use Panum’s region. of measures of Near Point of Fixation Disparity Sensitive measurement of fixation disparity and Associated Positive Fusional Convergence in in combination with specific instructions,12 conjunction with traditional diagnostic tests of thus, becomes a useful clinical tool for CI may be particularly useful in cases of milder evaluating binocular alignment inside Panum’s CI with concurrent symptoms of asthenopia area. As the cone density is greatest at the

57 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 fovea, there is likely to be little room for error the present study this correlation should be of fixation and, consequently, Panum’s areas larger for the NPFD and APFC than for the NPC are likely to be small41. Beyond a visual angle and PFC. of five degrees from the macula, Panum’s For the purposes of statistical analyses our areas measure approximately 6% to 7% of sample size with 25 CI and 35 control patients the angle of eccentricity.42 This increase in was adequately powered to detect medium-to the dimensions of Panum’s areas is in direct large effect sizes (d=0.65) for independent- relation to the decreasing cone density in the group t-tests.51 Moreover, Borsting et al.49 more peripheral regions of the retina. The reported their sensitivity of 95.7% and specificity larger extent of Panum’s area in the periphery of 87.5% for the CISS with only 47 children makes the peripheral visual field more tolerant with CI and 56 controls. We do, however, feel of larger degrees of disparity and less likely to that clinical trials on a much larger scale are undergo adaptations to avoid diplopia, such as in order to stabilize the proposed cutoffs and suppression.43 Thus the use of a peripheral fusion maximize the sensitivity and specificity of NPFD lock in some devices such as the Disparometer and APFC-based diagnosis. Due to the recent and the Wesson unit destabilizes44 and development of the NPFD target, normative data increases45 fixation disparity and under these and reliability indices have yet to be established. unnatural conditions fixation disparity may, therefore, be a less useful indicator of visual Conclusions stress and subsequent asthenopia,1 than if the The present study showed that the use fusion lock were located centrally. According to of the Near Point of Fixation Disparity test in Ukwade46 fixation disparity is approximately 1.5 combination with measurement of Associated to 3 times smaller when a combined central- Positive Fusional Convergence at near provides plus-peripheral fusion lock is used, compared a viable tool in diagnosis of symptomatic with a peripheral lock alone. More specifically, Convergence Insufficiency in children that can Carter15 reported forced vergence fixation be used in conjunction with traditional tests disparity values of 10 to 30 min arc with only of binocular function. This recommendation is a peripheral fusion lock and values that rarely also supported by recent findings of Poltavski exceeded 6 min arc with a foveal fusion lock. and Biberdorf 52 who showed that the NPFD The inclusion of a central fusion lock has also break equal to or greater than 15cm was been shown to result in less variability in the significantly predictive of lifetime history of measured values of fixation disparity.47 concussion in elite hockey players. At the same time the CISS scores in that study were not Study Limitations significantly different for concussed and non- In the present study we did not use the concussed players. Thus the use of the NPFD Convergence Insufficiency Symptom Survey and measurement of APFC are expected to (CISS) that has previously been shown to have increase the sensitivity of optometric evaluation 96% sensitivity and 88% specificity in clinical to CI without compromising its specificity. trials of children and adults by the Convergence Future investigations may also compare Classical Insufficiency Treatment Trial Study Group and Associated Positive and Negative Relative (CITT Study Group: Borsting et al.48,49,50). It Accommodation. Such studies are expected would thus be of interest to investigate the to improve our understanding regarding the relationship between CISS scores (pre and post- relationship of clarity to alignment, especially CI treatment) with corresponding measures when measured inside Panum’s area. of fixation disparity and associated positive fusional convergence. 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Convergence Insufficiency and Reading Study (CIRS) Group. 27. Jaschinski W. The Proximity-Fixation-Disparity curve and the Optom Vis Sci 1998; 75(2):88-96. preferred viewing distance at a visual display as an indicator 7. Cooper J, Duckman R. Convergence insufficiency: incidence, of near vision fatigue. Optom Vis Sci 2002; 79(3): 158-169. diagnosis, and treatment. J Am Optom Assoc 1978; 28. Maples WC, Hoenes R. Near point of convergence norms 49(6):673-80. measured in elementary school children. Optom Vis Sci 8. Shippman S, Infantino J, Cimbol D, et al. Convergence 2007;84(3):224-8. insufficiency with normal parameters. J Pediatr Ophthalmol 29. Scheiman, Mitchell, et al. “A randomized clinical trial of Strabismus 1983; 20(4): 158-61. treatments for convergence insufficiency in children.” 9. Schor CM and Ciuffreda KJ. Vergence Eye Movements: Basic Archives of ophthalmology 123.1 (2005): 14-24. and Clinical Aspects. Boston: Butterworths; 1983 30. Cushman N, Burri C. Convergence insufficiency. Am J 10. Panum P. Physiologische Untersuchungen uber das Sehen Ophthalmol. 1941;24:1044-52. mil zwei Augen. Schwerssche Buchhandlung: Kiel; 1858. 31. Passmore JW, MacLean F. Convergence insufficiency and 11. Mitchell D. E. (1966). A review of the concept of “Panum’s its managements: an evaluation of 100 patients receiving a fusional areas”. Am J Optom 1966; 43: 387-401. course of orthoptics. Am J Ophthalmol 1957;43(3):448-56. 12. Karania R, Evans BJW. The Mallett Fixation Disparity Test: 32. Scheiman M, Gallaway M, Frantz K et al. Nearpoint of influence of test instructions and relationship with symptoms. convergence: test procedures, target and normative data. Ophthal Physiol Opt 2006; 26: 507-522. Optom Vis Sci 2003; 80(3):214-25. 13. Lambooij M, Ijsselsteijn W. Visual discomfort and visual 33. Cuiffreda KJ. Near point of convergence as a function of fatigue of stereoscopic displays: A review. J Imaging Sci target accommodative demand. Optical Journal and Review Technology 2009; 53(3): 030201-14. of Optometry 1974; 111(3). 14. Cline, D., Hofsteller, H. W. and Griffin, J. R. (1989) Dictionary 34. Scheiman M, Wick B. Clinical Management of Binocular Of Visual Science, 4th edn. Radnor, PA Chilton, p. 205. Vision: Heterophoric, Accommodative and Eye Movement 15. Carter DB. Fixation disparity with and without foveal Disorders. Philadelphia, Pa: LippincottWilliams & Wilkins; fusion contours. Am J Optom Arch Am Acad Optom 1964; 2002. 41:729–36. 35. Vision Assessment Corporation. www.visionassessment.com 16. Sheedy JE (1980) Actual measurements of fixation disparity 36. Hosmer DW and Lemeshow S. Applied Logistic Regression. and its use in diagnosis and treatment. J Am Optom Assoc 2nd ed. John Wiley & Sons, Inc; 2000. 1980; 51:1079–1084. 37. Bewick V, Cheek L, Ball J. Statistics review 13: Receiver 17. Yekta AA and Pickwell LD. The relationship between operating characteristic curves. Critical Care 2004; 8(6): heterophoria and fixation disparity. Clin Exp Optom 1986; 508-12. 69: 228–231. 38. Borsting E, Rouse MW, Deland PN, et al. Association of 18. Mallett RF. Fixation disparity-its genesis and relation to symptoms and convergence and accommodative insufficiency asthenopia. Ophthalmic Optician 1974; 30: 1159–1168. in school-age children. Optometry. 2003; 74:25-34. 19. Sheedy JE, Saladin JJ. Association of symptoms with 39. Hedges L. Distributional theory for Glass’ estimator of effect measures of oculomotor deficiencies. Am J Optom Physiol size and related estimators. Journal of Educational Statistics Opt 1978;55:670–6. 1981; 6: 107–128. 59 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 40. Ferguson CJ. An effect size primer: A guide for clinicians and 47. Debysingh SJ, Orzech PL, Sheedy JE. Effect of a central fusion researchers. Professional Psychology: Research and Practice stimulus on fixation disparity. Am J Optom Physiol Opt 1986; 2009; 40(5): 532-538. 63: 277–80. 41. Carter, D. B. Studies of fixation disparity-historical review. 48. Borsting E, Rouse MW, De Land PN. Prospective comparison Am J Optom Physiol Opt 1957; 34: 320–329. of convergence insufficiency and normal binocular children 42. Ogle KN. Researches in Binocular Vision. New York: Hafner; on CIRS symptom surveys. Convergence Insufficiency 1964. and Reading Study (CIRS) group. Optom Vis Sci 1999;76(4):221-8. 43. Steinman SB, Steinman BA and Garzia RP. Foundations of Binocular Vision. A Clinical Perspective. McGraw Hill 49. Borsting EJ, Rouse MW, Mitchell GL, et al. Validity and Companies, New York; 2000. reliability of the revised convergence insufficiency symptom survey in children aged 9 to 18 years. Optom Vis Sci 2003; 44. Wildsoet CF and Cameron KD. The effect of illumination and 80(12):832-8. foveal fusion lock on clinical fixation disparity measurements with the Sheedy disparometer. Ophthalmic Physiol Opt 1985; 50. Rouse MW, Borsting EJ, Mitchell GL, et al. Validity and 5: 171–178. reliability of the revised convergence insufficiency symptom survey in adults. Ophthalmic Physiol Opt 2004;24(5):384-90. 45. Brownlee GA and Goss DA. Comparisons of commercially available devices for the measurement of fixation disparity 51. Faul F, Erdfelder E, Lang AG, Buchner A. G*Power 3: A flexible and associated phorias. J Am Optom Assoc 1988; 59: 451– statistical power analysis program for the social, behavioral, 460. and biomedical sciences. Behavior Research Methods 2007; 39: 175-191 46. Ukwade MT. Effects of nonius line and fusion lock parameters on fixation disparity. Optom Vis Sci 2000; 77 (6): 309-320. 52. Poltavski DV & Biberdorf D. Screening for lifetime concussion in athletes: Importance of oculomotor measures. Brain Inj 2014; 28(4) 475-485.

60 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 44th Annual Meeting Oral Papers and Posters

The following presentations and posters were presented during the 2014 COVD 44th Annual Meeting in San Diego, California.

Oral Paper Presentations

Author: Dmitri Poltavski, PhD Assistant Professor of Psychology Department of Psychology, University of North Dakota

Co-Author: David Biberdorf, OD, FCOVD Valley Vision Clinic Ltd ,. Grand Forks, ND

Title of Presentation: Screening For Lifetime Concussion In Athletes: Importance of Oculomotor Measures

ABSTRACT Background: In view of apparent insensitivity­ of traditional and computerized neuro­ psychological tests to the history of repeated concussion, further research is thus warranted to develop scientifically valid screening protocols for lifetime concussion incidence, which would assist in formulation of better concussion management protocols and return-to-play decisions. The purpose of the present study was to determine the utility of oculomotor-based evaluation protocols in screening for lifetime concussion incidence in elite hockey players.

Methods: 42 Division I collegiate male and female hockey players were evaluated using the guidelines of an overall oculomotor-based diagnostic clinical test protocol for the mTBI population. The sensitivity of the collected measures to lifetime concussion was then compared with the corresponding sensitivity of measures of neuropsychological functioning (ImPACT) often used with athletes for acute concussion diagnosis.

Results: Our model showed that a hockey player with a Near Point of Fixation Disparity (NPFD) break equal to or greater than 15cm, Visagraph comprehension rate less than 85% and the total score on part A of an ADHD questionnaire equal to or greater than 11 was on average 10.72 times more likely to have previously suffered a concussion than an athlete with lower values on the NPFD and ADHD questionnaire and a higher comprehension rate on the Visagraph. None of the IMPACT baseline assessment measures were significantly predictive of the individual’s concussion history.

Conclusions: While ImPACT continues to be an important instrument in immediate evaluation of a suspected concussion and in making return-to-play decisions, its utility in screening for a history of previous concussions and associated risks of repeat concussions including permanent neurocognitive decline is rather limited. The present study provides a relatively sensitive screening tool to assess the probability of previous concussion(s) in an athlete. This model may allow athletic personnel to address in a timely manner the risks associated with repeat concussions and to develop individualized concussion management protocols.

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Oral Paper Presentations, continued

Author: Benjamin C. Winters, OD, FCOVD

Title of Presentation: Oculomotor Training Improves Reading Fluency

ABSTRACT Background: The purpose of this study was to determine if adding oculomotor training (OMT) to an existing high school reading program would improve reading fluency outcomes.

Methods: In this prospective, single-blinded, cross-over trial, of high school students (n=53) in grades 9 and 10 enrolled in the school’s supplemental reading course, all students received reading intervention using Scholastic’s Reading180 system (New York, NY). In this 12 week study, students were randomized by classroom into 3 groups based on their initial training condition (+OMT, -OMT & placebo). +OMT used K-D Remediation training (Oakbrook Terrace, IL) with numerical stimuli presented at variable speeds in a left to right fashion to simulate eye movements required during reading. For placebo variable numerical stimuli were presented in a static central position stimulating minimal change in eye movement. After 6 weeks students in +OMT were crossed over to –OMT and vice versa. Students initially in placebo were crossed over into +OMT. The standardized Reading Curriculum-Based Measurement (RCBM) reading fluency test was given at 3 time points: at the start of the reading course, at the cross-over point and at the end of the reading course. The reading fluency test was given by an individual masked to the training conditions of the student and a words correct per minute (WCPM) score was determined.

Results: There was a significantly greater percentage improvement in reading fluency scores (WCPM) with combined OMT compared to reading intervention without OMT (7.54% vs. 3.59%, p = 0.03). Over the entire training period there was an average increase of 9.88 WCPM during sessions with OMT, 4.7 WCPM without OMT and 2.78 WCPM during placebo.

Conclusions: Expected improvement of a successful reading program is an increase of 5 WCPM. In this study, reading intervention coupled with OMT, resulted in nearly double the expected reading fluency improvement.

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Oral Paper Presentations, continued

Author: Eric S. Hussey, OD, FCOVD Private Practice Co-Authors: Bruce Moore, OD New England College of Optometry David Spivey, OD Private Practice Fuensanta A. Vera-Diaz, OD, PhD New England College of Optometry William Gleason Foresight Regulatory Strategies

Title of Presentation: The Eyetronix Flicker Glass Amblyopia Treatment Study: Acuity, Binocularity, Compliance and Satisfaction

ABSTRACT Purpose: Conventional amblyopia treatment includes refractive correction and penalization by patching or drops, which challenge binocu­larity and compliance. Current research and emerging clinical treatment of amblyopia are moving beyond simple penalization towards concurrent promotion of both improved binocularity and acuity. However, treatment still requires repetitive tasks and a high level of compliance. This Eyetronix Flicker Glass (EFG) clinical trial evaluates a novel amblyopia therapy that is more adaptable to daily activities, promotes binocularity, improves compliance, and maintains quality of life.

Methods: 24 subjects, ages 6-17 (mean 11±4 years), with mild to moderate anisometropic­ amblyopia (most having been previously and unsuccessfully patched), across 3 clinical sites wore the Eyetronix Flicker Glass (EFG) for near tasks of their choice, e.g., homework, video games, coloring. Eyetronix Flicker Glass (EFG) are glasses with liquid crystal lenses that rapidly alternate occlusion between the two eyes at a prescribed “flicker” frequency. For this study, subjects wore the EFG for 1-2 hours daily over their optical correction. Subjects were asked to wear EFG daily for 1-2 hours daily for a 12-week treatment period. Outcome measures were 1) change in logMAR acuity, 2) change in stereopsis, 3) compliance trackers, and 4) quality of life surveys.

Results: Visual acuity improved -0.12±0.11 logMAR. 92% improved in global and/or local stereopsis. Compliance, ease of use, parent-child relationship, comfort and preference over conventional (often prior) therapies were hugely positive. No adverse events reported.

Conclusions: Binocularity and compliance appear to be significant drivers of successful amblyopia therapy. The integrated design and task-unrestrictive nature of Eyetronix Flicker Glass improved acuity, promoted binocularity and was accepted by children needing therapy, suggesting a promising new treatment that lets kids be kids. 63 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 44th Annual Meeting Oral Papers and Posters

Oral Paper Presentations, continued

Author: Michael Gallaway, OD Associate Professor, Pennsylvania College of Optometry at Salus University

Co-Authors: Mitchell Scheiman, OD2, Christina L. Master, MD, CAQSM1, Arlene Goodman, MD, CAQSM1, Roni Robinson RN, MSN, CRNP1, Stephen R. Master, MD, PhD1, Matthew F. Grady, MD, CAQSM1, Lynn Mitchell, MS3 1Department of Pediatrics, The Children’s Hospital of Philadelphia, Philadelphia, PA; 2Pennsylvania College of Optometry at Salus University, 3Ohio State University College of Optometry

Title of Presentation: The Impact of Concussion on the Visual System of Children 11 to 17 Years Old

ABSTRACT Background: Although there are data describing the prevalence of concussion-related vision disorders in adults, there are currently no data in children Methods: In a prospective study, a consecutive­ sample of children 11 to 17 years old with a medical diagnosis of concussion were evaluated in a children’s hospital concussion program. Accommodative, vergence, and sacca­ ­dic testing was performed. Diagnosis of concussion was based on history, physical examination and neurocognitive testing with the ImPACT Test. Vision diagnoses were based on predetermined diagnostic criteria. Symptoms were assessed using the Convergence Insufficiency Symptom Survey (CISS). Results: One hundred patients were examined,­ with a mean age of 14.5, 58% were females and 65% had sports-related concussion. 29% were seen within a month of injury, 26% between 1 to 3 months, and 45% > 3 months. 69% had a diagnosis of one or more vision problems. The most common were accommodative disorders (51%), convergence insufficiency (49%), and saccadic dysfunction (29%). 46% of the subjects had more than one disorder with combined convergence and accommodative dysfunction the most common (23%). 70% of subjects had a medical diagnosis of vestibular dysfunction and 54% had both vision and vestibular dysfunction. The CISS correctly classified 81% of children with a vision disorder diagnosis (63 of 69 with disorder; 18 of 31 without disorder). Patients who were evaluated within 30 days after injury were more likely to have a vision diagnosis. Poor verbal memory (p=0.002) and visual motor speed scores (p=0.005) on the ImPACT Test were significantly correlated with the presence of a vision problem. Conclusions: The prevalence of ocular motor disorders in children after concussion is much higher than in a clinical population without a history of concussion. Clinicians should perform appropriate ocular motor testing in children who have had concussion. Further study is needed to determine optimal treatment methods. Funded by COVD, and the AMSSM Young Investigator Grant

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Poster Presentations

Author: Curtis Baxstrom, OD, FCOVD Adjunct faculty PUCO

Co-Authors: Graham Erickson, OD Jill Schultz, OD

Title of Presentation: Pacific University Vision Therapy, Rehabilitation and Pediatric Optometry Residencies

The purpose of this poster is to share with new students and members the three pediatric/VT and Rehabilitation Residencies.

Author: Marc B. Taub, OD, MS Southern College of Optometry Associate Professor

Co-Authors: Pamela Schnell, OD Southern College of Optometry

Title of Presentation: Optometry & Visual Performance: An International, Peer Reviewed Journal

Abstract Optometry & Visual Performance (OVP) is an international, peer reviewed journal dedicated to the advancement of the role of optometry in enhancing and rehabilitating visual performance. The mission of OVP is to increase the awareness and availability of clinically relevant information in functional, developmental, behavioral, and vision therapy aspects of optometry through an internet-based, open-access format. OVP, a collaborative effort of the Australasian College of Behavioural Optometry and the Optometric Extension Program Foundation, has an international circulation of more than 6000, including the membership of the representative organ­izations, optometry students, and residents. OVP covers a wide variety of topics, including clinical and scientific research, case reports and studies, reviews of new or adapted diagnostic or therapeutic methods, and editorials. Enhanced content such as author interviews, video demonstrations, and links to further resources can be found in the digital version. In addition to the scientific journal, OVP also publishes a regular blog, Visual Performance Today, which highlights current topics in behavioral vision, practice management topics, member news for the sponsoring organizations, book reviews, and much more!

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Poster Presentations, continued

Author: Patricia Cisarik Associate Professor, Southern College of Optometry

Title of Presentation: Vergence Facility: Testing Clinical Utility of 12 Bo / 3 Bi Prism Flipper Test

ABSTRACT Background: Gall, et al, (1998) found that vergence facility with 12 BO / 3 BI prism flippers differentiated between symptomatic and asymp­to­matic gradate students and staff at an optometry college (Vision Quality Scale, McKeon, et al., 1997), suggesting that vergence facility could be used to screen for nonstrabismic binocular disorders. This study investigated the relationship between horizontal vergence facility with 12 BO / 3 BI prism flippers and patient visual symptoms in a large clinical population.

Methods: Sixty-five nonstrabismic, nonam­bly­opic patients between the ages of 12-40 years who consecutively presented for vision exams were included if they were without ocular disease OU and not on medications known to affect ocular motility or accommodation. Symptomatic (score ≥ 27) and asymptomatic/borderline (score ≤ 26) subjects were defined using the Vision Quality Scale survey. Vergence facility with 12 BO/ 3BI at 40 cm was recorded using the subject’s habitual near Rx or no near Rx while the patient viewed a high contrast vertical line target.

Results: VQS scores identified 34 “asymptomatic/borderline”­ (mean VSQ score = 16.6; SD = 5.8) and 31 “symptomatic” patients (mean VSQ score = 37.8; SD = 9). A two-tailed t-test for independent samples showed that the difference in mean VQS score between the two groups was significant (p<.0001). Mean horizontal vergence facilities were 13.2 (± 7.8) cpm and 15.2 (± 6.4) cpm respectively for the “asymptomatic/borderline” and “symptomatic” groups. Neither a one- tailed or two-tailed t-test for independent samples indicated a significant difference in horizontal vergence facility between the two groups.

Conclusion: Near horizontal vergence facil­ity measured with 12 BO / 3 BI prism flippers did not correlate with symptoms on the Vision Quality Scale survey in a sample of patients from a large clinic population. Correlation of horizontal vergence facility with other near symptom surveys remains to be tested.

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Poster Presentations, continued

Author: Audra Steiner, OD, FCOVD Assistant Clinical Professor, SUNY College of Optometry

Title of Presentation: Subjective Sensory Testing as a Predictor for Successful Surgical Intervention

ABSTRACT Background: The decision to refer a patient with strabismus for surgical intervention should be made with gravity. All involved desire a positive outcome. Residual or consecutive strabismus represents surgical failure from the patient’s point of view; the optometrist finds this result objectionable as it inhibits development of high-quality binocular vision. Appropriate subjective sensory testing performed before surgical referral can help clarify case prognosis. With better understanding, patients can make informed decisions about their care.

Case Summary: Four patients presented for evaluation of strabismus: two with esotropia and two with exotropia. Each expressed an interest in vision therapy and strabismus surgery.

Results: Three patients were referred for surgery. Two had a positive outcome, with good alignment and binocularity. One was left with constant diplopia. The fourth was deemed a poor surgical candidate. Evaluation of subjective findings was a strong predictor of good alignment and development of binocular vision post-surgically.

Discussion: The major amblyoscope is often considered first for sensory testing in a strabismic patient, but, even in a vision therapy office, not everyone has one, and doctors who do not practice vision therapy also refer patients for strabismus surgery. Presence of sensory fusion is a strong predictor for success in vision therapy and surgery, though patients with very large deviations might not be able to develop the vergence ranges required to maintain fusion. Having a basic battery of tests that can be done in many settings, without highly specialized equipment, and understanding the implications of correspondence patterns allows doctors to better educate patients. Optometrists should partner with surgeons who are receptive to our understanding of the cortical intricacies of binocular vision and who welcome our opinions. The author of this poster needs report no conflicts of interest.

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Poster Presentations, continued

Author: Christina Grosshans, OD Resident, Southern College of Optometry

Co-Author: Kelley Dasinger, OD, FAAO

Title of Presentation: Spasm of the Near Reflex: 2 Case Reviews with Psychogenic Factors as Etiology of SNR

ABSTRACT Background: Spasm of the near reflex (SNR) presents with intermittent and variable esotropia, miosis, and accommodative spasm. The condition is infrequently diagnosed, and often misdiagnosed with differentials including lateral rectus palsy, myasthenia gravis, and latent hyperopia. The etiology of SNR is often a psychogenic factor although organic causes must also be considered. Diagnosis is difficult due to the intermittent nature of the spasm causing fluctuating results on acuities, cover test, retinoscopy, and refraction. The treatment of SNR is prolonged and often very difficult and includes a multi-disciplinary approach.

Case Summary: A 22 year old female pre­sented for a vision therapy evaluation complaining of constant double vision and daily headaches for the last several years. The patient demonstrated cover test results from 8^ exophoria to 40^ alternating esotropia with -7.00 DS myopia on retinoscopy OU. Humphrey visual fields revealed a constricted field characteristic of psychogenic factors. These findings combined with pre and post-dilation miotic pupils confirmed the diagnosis of SNR. Treatment over the past 3 years has included multiple pharmacologic agents with unsuccessful results, and ophthalmic lenses with yoked vertical prism and low plus lenses ultimately providing resolution of symptoms. A 13 year old female with a history of juvenile delinquency, bipolar disorder, and emotional outbursts presented complaining of blurred vision and ocular discomfort. Over two examinations, acuity fluctuated from 20/250 to 20/20 with a variable 20^ intermittent alternating esotropia coinciding with miotic pupils and -4.00 DS myopia. Plus lenses were prescribed and the patient is to return for follow up in the coming weeks.

Discussion: These cases demonstrate the presence of psychogenic factors as the etiology of SNR. There are multiple proposed treatments for SNR that have shown modest success. Therefore, it is possible that the most important aspect of treatment is psychological and this aspect must not be overlooked.

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Poster Presentations, continued

Author: Mosaad Alhassan, BSc (Optometry), MSc, PhD Candidate School of Optometry and Vision Science, University of Waterloo

Co-Author: Jeffery Hovis , OD, PhD, FAAO School of Optometry and Vision Science, University of Waterloo

B.Ralph Chou, OD, MSc, FAAO School of Optometry and Vision Science, University of Waterloo

Title of Presentation: Rebeatability and Validity Measurements of Associated Phoria Tests: MKH-Haase Charts and Other Commercially Available Tests

ABSTRACT Background: H.J.-Haase developed a system­ ­atic set of tests for evaluating binocular vision called the Pola Test. The Pola test measures associated phoria and stereo acuity at distance and near using a variety of different targets for each. This testing method and interpretation is referred to as MKH-Haase method. The MKH method is more commonly used in Germany and other European countries than English speaking countries.

Purpose: To investigate the test-retest repeatability of near horizontal associated phoria tests using MKH-Haase charts and other common clinical tests.

Methods: Near horizontal associated phorias values were measured for 34 symptomatic and 40 asymptomatic participants using 11 different tests on two different occasions. Symptomatic and asymptomatic was determined by a questionnaire regarding visual symptoms at near.

Results: Except for the Sheedy Disparometer, the mean differences between sessions for the near horizontal associated phoria tests was not statistically significant different from zero based on the 95% confidence interval. The mean between-session difference for the Sheedy Disparometer was significantly more exo at the second session for the asymptomatic group. The 95% limits of agreement for Mallet Unit and AO Card for both groups, and Saladin Card for the asymptomatic group were within ± 1.00 D and for most of the other tests were about ± 2.00 D. The exceptions were the symptomatic groups Disparometer limits, which were -4.25 to 5.75 D. The linear regression (r) between the first and second session results were about 0.7 and significant for most tests. Again the exception was the Sheedy Disparometer where the regression was about 0.3 for both groups.

Discussion & Conclusions: Most of tests showed good repeatability for both subject groups at near, except the Sheedy Disparometer. The reason for the lower repeatability could be the design of the test due to the lack of central fusion locks.

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Poster Presentations, continued

Author: Poonam Nathu Resident, Dr . Shidlofsky, SCO

Title of Presentation: Measuring Efficacy of Therapeutic Prism Lenses with the Computerized Dynamic Posturography In Patients with Tbi and a Learning Related Vision Problem.

Abstract Background: Computerized Dynamic Pos­tur­­ography (CDP) is a technique used to objectively quantify the variety of sensory, motor and central adaptive impairments involved in balance control. The objective of the case report is to demonstrate the impact of therapeutic prism lenses on posture and perception, measured with CDP, in traumatic brain injury and learning related vision problem patients.

Case Reports: A 16 year old male, who suffered a traumatic brain injury during a football game, initially presented with the following symptoms: headaches with any visual stimulation, photophobia, trouble converging, non-specific eye pain, blurred vision, and postural changes. A series of chair procedures and baseline neuro-sensory testing, including CPD, showed visual spatial disorientation, binocular vision dysfunction, imbalance, ocular motor dysfunction, and convergence insufficiency. Therapeutic lenses (2 base down, with a BPI FL-41 tint) was prescribed for full time wear based on the initial examination results; testing was repeated. A 9 year boy presented with complaints of holding material close, headaches and eye rubbing associated with desk work, moving print, light sensitivity, loss of reading comprehension, loss of place and skipping lines when reading, and difficulty with concentrating. After a series of chair procedures and the neuro-sensory testing were performed, the data showed binocular vision dysfunction, convergence insufficiency and accommodative dysfunction. Therapeutic lenses (3 base down) were prescribed for full time wear. The results of both cases show improvement in all areas of testing, especially the CDP results. Looking at the sway velocity when isolating sensory integration function, primary proprioception, primary visual, and primary vestibular, there was a significant improvement in each of these sensory areas with the use of therapeutic prisms.

Discussion: These cases demonstrate the benefit of therapeutic prism lenses. Postural and perceptual changes, which can be quantified by the CDP, will be highlighted.

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Poster Presentations, continued

Author: Susan Evans, OD Resident, Southern College of Optometry

Co-Author: Glen Steele, OD Southern College of Optometry

Title of Presentation: Promoting Visual Development in Infants with Hydrocephalus

Abstract Background: Hydrocephalus is associated with refractive errors, strabismus, increased intraocular pressure, and cortical blindness in children Visual perceptual problems associated with hydrocephalus include visuospatial performance, material organization, and visual attention deficits. Hydrocephalus can impact the child’s visual as well as overall development. This case report serves to review the visual performance and visual perceptual deficits that can occur in hydrocephalic infants.

Case Report: A twelve month old male with a history of hydrocephalus reported to The Eye Center at Southern College of Optometry on February 20th, 2013. Although all ocular health was observed to be normal, the child was unable to fix and follow any lights or objects. He was diagnosedwith oculomotor dysfunction, and his grandmother was instructed begin at-home activities to stimulate visual development. Proceeding multiple follow-up examinations and continuous at-home visual stimulation activities for one year, the child was exhibiting excellent visual fixation, oculomotor function, and convergence abilities.

Conclusion: The American Optometric Association recommends visually stimulating activities for all infants to promote appropriate visual development; however, stimulating activities may be especially important in the development of appropriate visual function in hydrocephalic children. This poster will highlight the hydrocephalus, as well as the activities performed to enhance visual development.

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Poster Presentations, continued

Author: Chrissy Ulrich, BS 3rd year student, Southern College of Optometry

Co-Author: Marc B. Taub OD, MS, FAAO, FCOVD Southern College of Optometry

Title of Presentation: A Comparison of Accommodative Amplitude with Multifocal Contact Lenses to Bifocals

Abstract Background: Spectacle plus lenses are commonly used to alleviate symptoms of near tasks caused by lack of accommodative ability of the visual system. Multifocal contact lenses offer another treatment option for those not wanting bifocal spectacles. This study compared accommodative lag and amplitude between the Bausch & Lomb Pure Vision low addition multifocal contact lens and +1.25D lenses in bifocal spectacles.

Methods: This study was a randomized cross-over experiment with established spher­ical soft contact lens wearers (N=40; ages 21-35). Subject’s accommodative lag (Grand Seiko WR-5100K Auto Refractor) and accommodative amplitude (Push-up method and Minus lens to blur method) was measured on the subject’s dominant eye under three conditions: baseline measurement through subject’s habitual spherical soft contact lens, after three days of wear through +1.25D bifocal glasses over subject’s habitual distance contact lens, and after three days of wear through Bausch & Lomb Pure Vision low addition multifocal contact lens. The order of procedures (multi­ focal contact lens or spectacle) and testing was randomized. Data were analyzed using repeated measures regression methods.

Results: There were no significant between-condition differences on the Push-up method. There was a significant difference between Baseline and Multifocal conditions for the Minus lens to blur method (p= .04). For the Grand Seiko spherical reading, there was a significant overall Condition effect (p< .001), and significant differences between Baseline and Multifocal (p= .003) and Bifocal and Multifocal (p< .001) conditions.

Conclusion: This study confirms a multi­focal contact lens produces differences in accommodative lag compared to a traditional flat top bifocal. This study also demonstrates differences in accommodative amplitude between multifocal and no lens. In both cases, the multifocal lenses cause the desired response of increasing accommodative amplitude and decreasing accommodative lag. Further research is needed with various lens designs to determine the most appropriate choice for patient care related to accommodative problems.

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Poster Presentations, continued

Author: Kristen Davis, BS Southern College of Optometry

Co-Author: Marc B. Taub OD, MS, FAAO, FCOVD Southern College of Optometry

Title of Presentation: Contrast Sensitivity Testing in Normal Vision: Performance with Letter vs. Continuous Text

Abstract Purpose: Contrast sensitivity is an essential feature of vision that provides information about visual function. There are numerous commercially available tests to measure contrast sensitivity. The present investigation compared contrast sensitivity measured with letter stimuli to contrast sensitivity measured with paragraph stimuli in a non-low vision based population.

Methods: Participants consisted of adults (22-35 yo) with best-corrected vision of 20/32 at near and stereocuity ≥ 30 seconds of arc. The study was conducted using the Adult Near Contrast Test, consisting of both EDTRS format letter charts and continuous text charts at five different contrast levels. The total number of letters (EDTRS chart) and words (continuous text chart) was recorded at each contrast level. Testing proceeded in decreasing order of level of contrast for each chart type. Repeated measures ANOVAs were conducted to examine the effects of contrast level on (a) total letters (EDTRS letters format) and (b) total words (continuous text format).

Results: Significant differences based on contrast level were found for total letters (p< 0.001) and for total words (p< 0.001). A Pearson correlation was performed between total letters and total words for each contrast level. High and statistically significant correlations between words and letters occurred at all contrast levels (p< 0.001), except for the 100% contrast targets (p= 0.69).

Conclusion: A positive correlation was found between the two testing formats contained in the Adult Near Contrast Test for measuring contrast sensitivity in adults with normal vision. Further testing will explore this relationship in a low vision patient population.

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Author: Lindsay Wettergreen, OD Vision Rehabilitation Resident at Southern College of Optometry

Co-Authors: Glen T. Steele, OD, FCOVD, FAAO Southern College of Optometry Marc B. Taub OD, MS, FAAO, FCOVD Southern College of Optometry

Title of Presentation: Unique Retinoscopy Findings in A-pattern Esotropia

Abstract Background: The pathophysiology of A-pattern esotropia is not fully understood. Without complete understanding of a condi­tion, it is difficult to determine proper testing necessary to identify accompanying characteristics. Retinoscopy is a critical tool in the examination of the pediatric population and can be used for more than determining refractive error. The purpose of our paper is to report on a patient with A-pattern esotropia and the abnormal retinoscopy findings.

Case Summary: We report a 3-year-old female with a history of congenital nystagmus and esotropia noted by her mother, especially in up-gaze. Upon examination, A-pattern esotropia was observed. Retinoscopy findings showed equal and low plus reflex in right, left and down gaze. Up-gaze revealed inward deviation of the left eye and marked equal darkening of the reflex in both eyes, equal pupil constriction of both eyes and equal against-motion reflex of both eyes of approximately 2 diopters. We prescribed monocular home eye stretches, emphasizing upward and outward directions, and recommended 3-month follow-up evaluation.

Discussion: The cause of the unusual retin­o­scopy findings associated with the A-pattern esotropia is unknown. We hope that this case report will encourage the use of retinoscopy for other reasons than determination of refractive error and inspire further investigation and monitoring of A and V-pattern strabismus.

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Author: Jae-do Kim Associated Professor/School of Optometry Kyungwoon University

Co-Author: Kenneth Ciuffreda SUNY State College of Optometry

Title of Presentation: Effect of Partial Presnel Prisms for Exotropia with Suppression at Distance: Pilot Study

Abstract Background: Most exotropes have fusion at near, but frequently exhibit suppression at distance. Until now, anaglyphs for fusion training, or patching of the dominant eye, have typically been used for anti-suppres­sion.However, these methods can pose problems, such as limitation of gaze range and/or return of the suppression. We used a novel approach in such patients with good success in a small sample of children.

Methods: 5 patients with exotropia without­ history of strabismus surgery or ocular disease participated. Ages were 6-10 years. Mean deviation at distance was XT 20+/-3pd (range 18-25pd) and XP 18+/-15pd (range 3-39pd) at near, as assessed by the cover test. Two suppressed in the RE and 3 in the LE at distance as assessed by the Worth-4-Dot test. For vision rehabilitation, all patients wore their distance spectacle prescription in conjunction with sector, base-in Fresnel prisms equivalent to the distance deviation in the upper region of the non-suppressing eye’s spectacle lens. In addition, vergence-based vision rehabilitation was added once the suppression reduced/ dissipated.

Results: After 3.8 +/- 2.2 (range 1-6 mos.) months of wearing the spectacles, suppression was not present at distance, and fusion was now readily evident. This was followed by conventional fusion training ( 9+/-3 mos., range 6-12 mos.) to enhance/embed the earlier positive prism effect, with positive results.

Conclusions: This simple, sequential, two-pronged approach to distance suppression and fusion in children with XT/XP resulted in excellent results in this small sample of children. The first phase appears to facilitate the second. This should now be tested in a larger sample of such patients.

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Author: Tanya Polec OD, FCOVD Head Administrator / Visual IntelligenceTM

Co-Author: Amy Schlessman, PhD Rose Academies

Title of Presentation: Vision Development as Innovation at a Public High School

Abstract Background: The Educator’s Guide to Classroom Vision Problems emphasizes the importance of vision development for young children and through elementary school. Almost all traditional high schools do not develop visual intelligence as a fundamental element for academic and life success. We explored how a credit-bearing course on Vision Development might open options for students at a high school serving a high-risk student population.

Methods: A neuro-optometric medicine practice and alternative education campus conducted a pilot research study using a quasi-experimental research design. Data were collected using an extensive pre-post battery of assessments, e.g. TVPS, King Devick, Binocular Vision Assessment Program’s fusional ranges, Woodcock-Johnson visual memory subtests. Purposive sampling assigned students to treatment/control.­ Treatment group participated in a 3 month high school course with state standard aligned curriculum on “science” of vision plus vision therapy lab sessions featuring base in-out activities, space matching, yoked prism, etc.

Results: Assessment of students at school before sampling showed 82% (80/98) of the student population in need of vision therapy. Despite attrition, students receiving treatment­ (n = 13) showed statistically significant improvement on multiple assessments: TVPS mean 19.5 pts. higher than control, p < .001 Fusional Ranges, Binocular Vision Assessment Program BI Break mean 6 pts. higher, p <.01 BI Recovery 7 pts higher, p <.01 BO Break 14 pts. higher, p<.05 BO Recovery 17 pts higher, p = .05 King Devick mean lower time, 12 sec, p<.05 less errors, 1.2, p<.05 Woodcock-Johnson Visual mean 11 pt. decrease in Memory, subtest errors, p<.01

Discussion: Results of this study indicate that offering vision development at a public high school may significantly increase students’ visual capabilities and skills that are fundamental to academic success thereby expanding life options.

76 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 44th Annual Meeting Oral Papers and Posters

Poster Presentations, continued

Author: Tyler Phan Primary Eye Care/Acquired Brain Injury & Vision Rehabilitation Resident

Co-Author: Carl Garbus, OD Family Vision Care, Valencia, California

Title of Presentation: Stress Induced Diplopia: A Case Report

Abstract Background: Emotional stress and increase near work demand are well described triggers for developing a decompensated phoria. One explanation is through the binocular imbalance resulting in psychological and behavioral changes. This case describes the use of Fresnel prism for immediate relief of symptoms, in addition to stress control and vision therapy, and gradual removal of prism dependency.

Case Summary: An 18-year-old Caucausian female college student experienced sudden onset of horizontal binocular diplopia accompanied by mild headache post viral-like upper respiratory illness and one month after starting college. Neuro-opthalmic testings two months after initial onset revealed 15 diopter of intermittent comitant right esotropia at distance and near. General neurologic exam was otherwise unremarkable, including pupils and oculomotility. MRI of the orbit and brain was negative. All blood work for various systemic diseases were normal. Patient was diagnosed with stress induced decompensated phoria with possible inciting factors of viral-like illness and increase near work demand.

Results: Patient was prescribed 10 diopter of Fresnel prism over right eye for immediate relief of symptoms. Additionally, patient underwent active home therapy to increase fusional vergence reserves. Patient was educated about inciting factors and had special accommodations at school to keep stress level down. At 3, 5 and 6 months follow-up, the amount of prism was reduced to 6, 2 and 0 diopter, respectively, with patient maintaining clear and comfortable single vision.

Discussion: This report demonstrates the importance of a thorough case history with complete work-up to rule out potentially life-threatening etiologies. Equally important is to inquire about associated factors because stress can cause many visual disturbance, which may include diplopia. This case shows that with proper stress management, a motivated patient can regain control of her binocular system. Intermittent prisms and vision therapy are also important treatment modalities to consider in addition to lifestyle changes.

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Poster Presentations, continued

Author: Gale Orlansky Optometrist/Assistant Professor/Salus University

Title of Presentation: Longitudinal Study of Vision Screenings of Preschoolers: What Happened to Those Children who Failed Their Screening?

Abstract Background: In the US more than 12.1 million school-age children have a vision problem; only one in three children receive eye care services before six years. The NEI reports that the most prevalent and significant vision disorders of preschoolers are amblyopia, strabismus, and significant refractive error.1 Preschool vision screenings identify children who may have a vision disorder which can lead to permanent visual impairment unless treated in early childhood. For vision screenings to be effective, a “follow-up” vision care plan needs to be in place.

Methods: From 1999 to 2013, children who were enrolled in an inner city Head Start program underwent vision screenings. The vision screening was based on the Modified Clinical Technique and included: visual acuity, cover test, non-cycloplegic static retinoscopy, and direct ophthalmoscopy. Children who had reduced visual acuities, strabismus, high phorias or any observable ophthalmic abnormalities were referred for further eye care. A longitudinal review of encounter records was made, and the following information was recorded: the number of children who had their vision screened, the number who failed the screening, and the number of children who received follow-up care.

Results: Over 15 years, 36,156 Head Start preschoolers had their vision screened, and 5409 were identified as failing their screening. Of those children who failed the screening, only 30.9% received follow-up care. A review of a subset of records from 2010-13, showed 15,484 children were screened and 2344 failed the screening. Of those who failed 22.4% received follow-up care; 55.8% received eyeglasses, 31% were told to return for eye care in 6 months, 20.6% were given no optical treatment, 1.3% had surgery.

Conclusions: As optometrists we need to make a commitment ensuring continuing eye care for preschoolers post screening by improving eye health literacy, and accessibility to comprehensive vision care services.

1www.HHS.gov

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Author: Derek Tong, OD, FAAO, FCOVD, FNORA Adjunct Clinical Assistant Professor, Southern California College of Optometry

Title of Presentation: Private-Practice Residency Program in Pediatric Optometry & Vision Therapy/Neuro-Optometry

Abstract This residency program is a full-time, formal, supervised program consisting of direct patient care, didactic education, teaching experience, and scholarly activities. It is based at the Center for Vision Development Optometry, the private practice of Dr. Derek Tong located in Pasadena, California. The learning objectives are achieved through patient care, case studies, and seminars which will facilitate the resident’s development into an expert clinician in the areas of pediatric optometry, binocular vision, vision development, neuro-optometry, and vision enhancement. A unique component of this program is equipping the resident with the necessary practice management skills to operate a private practice and successfully market its unique services. The resident will also learn to interact and co-manage patients with other optometrists, child development specialists, educators, and rehabilitation professionals. This program provides qualified graduate optometrists with advanced clinical experience in the diagnosis and management of pediatric eye diseases, binocular vision disorders, visual-perceptual dysfunctions, acquired brain injury, and other functional vision deficits. Link to residency website: http://tinyURL.com/VisionResidency

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Poster Presentations, continued

Author: Tomohito Okumura, MSOptom, MEd, FAAO, FCOVD-I Osaka Medical College LD Center

Co-Authors: Hiroshi Watanabe, PhD1 Eiji Wakamiya M.D. PhD.2,3 Hiroshi Tamai M.D. PhD2,4 1National Institute of Advanced Industrial Science and Technology, 2Osaka Medical College, LD Center, 3Aino University, Faculty of Nursing and Rehabilitations, 4Osaka Medical College, Department of Pediatrics

Title of Presentation: Relationship Between Topographical Orientation and Visual Perception in Young Adults

Abstract Background: Topographical orientation is the ability to orient and navigate in both familiar and unfamiliar environment (Wang and Spelke 2002). This complex function relies on several perceptual and cognitive processes such as attention, memory, perception and decision-making skills, all of which play important roles in spatial orientation (Lepsien and Nobre, 2006). Topograophical orientation is possibly related to basic visual perception such as visual discrimination skill. The present study is aimed at investigating whether visual perception is related to topographical orientation perform­ance in young adults.

Methods: 17 young adults with normal visual acuities and stereopsis served as subjects and devided into two groups; good (GVD) and poor visual discrimination (PVD) groups, by using visual discrimination subtest in Test of Visual Perception Skills (TVPS-3). A immersive virtual reality system, CAVE (Computer Assised Virtual Environment) was used to assess topographical orientation performance of all subjects. The CAVE is contained a cube-shaped room in which the walls (3m x 3m) are rear-projection screens. 3D images within the CAVE appear to float in mid-air. The subjects, who wears polarization glasses, can walk around in the room for assigned tasks. Sensors within the room track the subject’s position to align the perspective correctly and measured subject’s walking trajectory. The subjects were asked to find a target as quick as possible in 2, 4, or 8 square poles arranged in the virtual reality room which is randomly roteted around a vertical axis for each trial. The durations to find a target were measured and analyzed to investigate the relationship between topographical orientation and visual perception.

Results: Compared to the GVD group, durations to find a target in the PVD group were significantly longer. Discussion: Our results indicate that visual discrimination skill, one of basic visual perception, was related to topographical orientation performance in young adults.

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Author: Rochelle Mozlin, OD, MPH Associate Clinical Professor, SUNY State College of Optometry

Title of Presentation: Hyperopic Children and the Application of Evidence-Based Optometry

Abstract Background: Hyperopia is the most com­mon refractive error in children. In the past 10 years, significant research on hyperopia has been conducted. The addition of these studies to the evidence-base should help optometrists make better decisions about when and what to prescribe for hyperopic children.

Case Summary: TJ, a 2 year old girl presented to the Pediatric Service of the University Eye Center with her mother. TJ’s mother had no concerns about TJ’s vision but thought an eye exam would be a good idea. TJ was in good health. Her overall development was normal. There was no family history of significant visual conditions. Uncorrected visual acuities at both distance and near, measured with pictures were 20/30 right eye, left eye and both eyes. Pupils and EOMs were normal. Cover testing at both distance and near was ortho. Retinoscopy was +2.00 in each eye. With cycloplegia, retinoscopy was +3.00 in each eye. Ocular health assessment was completely normal.

Results: What would you do?

Discussion: The results of 4 recent studies will be summarized: Cotter SA, Varma R, Tarczy-Hornoch K, McKean-Cowdin R, et al. Risk factors associated with childhood strabismus. (2011) Kulp MT, Ying G, Huang J, Maguire M, et al. Associations between hyperopia and other vision and refractive error characteristics. (2014) Van Rijn LJ, Krijnen JSM, Nefkens-Molster E, Wensing K, et al. Spectacles may improve reading speed in children with hyperopia. (2014) Ciner EB, Ying GS, Kulp MT, Maguire MG, et al. Stereoacuity of preschool children with and without vision disorders. (2014)

Conclusion: In the management of hyper­opia in young children, evidence-based optometry is focusing on risks associated with uncorrected hyperopia and the potential benefits of intervention. Optometrists are likely to continue to practice with a variety of prescribing philosophies, but incorporating an evidence-based perspective into management strategies will enhance outcomes for these young patients.

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Poster Presentations, continued

Author: Ruth Y. Shoge Assistant Professor, Salus University Chief, Pediatric and Binocular Vision Services

Title of Presentation: Caring For Invisible Wounds: Vision, The Brain, and Beyond – A Case of an Adolescent Recovering from an mTBI

Abstract Background: Mild traumatic brain injuries (mTBI) are a common occurrence in children and adolescents. Postconcussive symptoms are complaints that tend to occur more often following TBI and include a range of somatic (e.g., headache, fatigue), cognitive (e.g., inattention, forgetfulness, slowed processing), and affective symptoms (e.g., irritability, disinhibition). Neurological, psychological, and physical factors are seen as interacting in complex ways, and appropriate evaluation allows for selecting individualized treatments for different patients depending on the particular dynamics of their disability. This case reviews the management of one such patient.

Case Summary: A 17 year old female presented with symptoms including reduced vision, diplopia, headaches, and photophobia. Most concerning was her reported inability to read and write. She had plans to sit for the SATs, graduate from high school, and attend college. Subsequent treatment of her visual symptoms with VT, direct and constant communication with her parents, and coordination with her care team resulted in this patient being able to graduate on time, and successfully gain acceptance to several colleges.

Discussion: Vision: Visual problems follow­ing an mTBI have been well documented over the years. Many of the common symptoms include oculomotor dysfunction, diplopia, blurry vision, and photophobia. The Brain: mTBI can affect all aspects of brain function. In this case, we had to confront the patient’s visual symptoms, psychosomatic issues, and visual apperceptive agnosia-like symptoms. Beyond: Compounding these problems were also the social aspects of her recovery – being out of school and away from friends, and the uncertainty of her future. As professional and media awareness con­tinues to increase, optometrists will find themselves at the forefront of caring for these patients. It is our responsibility to provide vision care, and to be a team-player in the integrated treatment of the mental, emotional, and social health of these patients.

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Author: Derek Tong, OD, FAAO, FCOVD, FNORA Adjunct Clinical Assistant Professor, Southern California College of Optometry

Co-Authors: WC Maples OD, MS, FAAO, FACBO, FCOVD Professor Emeritus, Northeastern State University: Oklahoma College of Optometry Research Professor, William Carey University: College of Osteopathic Medicine Judy Tong OD, FAAO Associate Professor & Assistant Dean of Residencies, Southern California College of Optometry at Marshall B . Ketchum University

Title of Presentation: 10 Key Steps to Start a Private Practice Vision Therapy Residency

Abstract Background: The first private practice vision therapy residency program was launched in 2008. Since then, many new programs have been established. Due to the on-going demand, a huge need for additional program positions is anticipated.

Methods: This article provides an overview of the process involved to start and receive accreditation for such residency programs.

Results: Resources and links are included.

Discussion: The 10 key steps to starting a residency includes goals & intention, feasibility analysis, initial proposal, optometry school affiliation & adjunct faculty appointment, self study preparation, recruitment of initial resident, ACOE site visit, accreditation report, accreditation approval, annual review & next accreditation visit.

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Poster Presentations, continued

Author: Lynn H. Trieu, OD, MS, FAAO Assistant Professor at Salus University

Co-Author: Ruth Y. Shoge, OD, FAAO Salus University

Title of Presentation: The Pediatric/Vision Therapy Residency at Salus University

Abstract Background: The Pediatric/Vision Therapy Residency at The Eye Institute of the Pennsylvania College of Optometry (PCO) at Salus University, one of the first such residencies in the country, was established in 1977. It is a challenging 54-week educational program that is designed to train entry-level graduate optometrists to provide competent and efficient care to pediatric and infant populations, vision therapy, and neuro-optometric vision rehabilitation. One of the biggest attractions of PCO is its exceptionally strong clinical program. From day one, residents get invaluable experience with our diverse patient population. The Pediatric/ Vision Therapy Residency provides the foundation for the management of binocular disorders, strabismus, amblyopia, traumatic brain injuries, learning-related vision problems, and vision therapy. Additionally, our Pediatric/Vision Therapy residents rotate through our affiliated hospital vision clinics, which specialize in pediatric ocular disease and neuro-optometric vision rehabilitation. Residents also have the opportunity to enhance their skills in the diagnosis and management of ocular disease through our specialty services, such as emergency eye care, neuro-optometry, and retina service. The science-and research-driven atmosphere provides a unique learning and teaching experience for the residents as they work closely with faculty and students in the clinic. The Pediatric/Vision Therapy Residency at PCO is a comprehensive program that assiduously prepares residents for the fields of pediatrics, vision therapy, and neuro-optometric vision rehabilitation. The residency employs an appropriate level of supervision and support from highly- trained faculty and eventually leads residents to clinical independence. With the recent renovation of The Eye Institute, the introduction of The Brain Injury Clinic, and new affiliated hospital sites, it has never been a more exciting time for residents at this institution.

84 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 44th Annual Meeting Oral Papers and Posters

Poster Presentations, continued

Author: Helena Tzou Pediatrics and Vision Therapy Resident at Southern College of Optometry

Title of Presentation: Vision Therapy for Children With Non-Verbal Autism: Uploading and Downloading for Success

Abstract Background: Vision therapy for children with non-verbal autism can enhance quality of life. Adaptability during planning and implementing of therapy sessions can allow patients to increase visual ability as well as develop skills that can influence all facets of life.

Case Summary and Results: An eleven-year-old male with non-verbal autism and history of psychological and neurological conditions, learning problems, and refusal to wear glasses was evaluated. Case history revealed that the patient often loses his place while reading, reads slowly, uses his finger as a marker, is bothered by light, experiences difficulty catching or hitting a ball, writes poorly, and has an awkward or immature pencil grip. The child was diagnosed with intermittent exotropia, oculomotor dysfunction, binocular dysfunction, accommodative dysfunction, strabismic amblyopia, and hyperopia astigmatism. Eight weeks of two sessions a week of optometric vision therapy was prescribed. Throughout therapy, various tech­niques were simplified in order for the patient to understand the task and to enhance visual skills. Additional aspects of the techniques were added when possible. The patient wore glasses more frequently at home and tolerated an eye patch for monocular activities; the patient participated in home vision therapy sessions more willingly and repetitive behaviors decreased. The patient’s mother reported greatly improved handwriting, verbal skills, and initiative to attempt new tasks. Mild improvement in ocular motilities, convergence, and binocular ranges were measured at the progress evaluation.

Discussion: Children with non-verbal autism or other significant deficits due to autism can benefit from optometric vision therapy. It is often more effective if patient’s ability level is gauged and activities are modified for success.

85 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 44th Annual Meeting Oral Papers and Posters

Poster Presentations, continued

Author: Eric S. Hussey, OD, FCOVD Private Practice

Title of Presentation: Development of Stereopsis Using Eyetronix Flicker Glass to Treat Amblyopia in a Congenital Unilateral Post-Cataract-Surgery Aphake

Abstract Background: Early or congenital cataract is treated with early surgery, commonly without pseudophakic implants. Surgery is often followed with patching and optical correction, including extended wear contact lenses. Some level of amblyopia is expected to persist depending on how early surgery was performed and what post-surgical therapies are accomplished.

Case Summary: As a parallel case study to the Eyetronix Flicker Glass Amblyopia Treatment Study, a 5-year old white female unilateral (post-surgical) aphake was treated with the novel therapy. Eyetronix Flicker Glass (EFG) are glasses with liquid crystal lenses that rapidly alternate occlusion between the two eyes at a prescribed “flicker” frequency. The patient had been previously fit with an extended wear pediatric aphakic contact lens and had been faithfully patching for 4 hours daily. In this case study, we followed the Eyetronix study protocol of wearing EFG for near activities (e.g., coloring) for 1-2 hours daily for a 12-week treatment period. Given positive results and strong interest in continuing treatment by the patient parents and doctor, therapy has been extended for an additional 12 weeks. At this time (12-weeks as of this abstract), acuity in the amblyopic aphakic eye has improved from LogMAR 0.34 to 0.26. In addition, stereopsis has improved from <500 seconds (no response on stereo tests) to a reliable 63 arcseconds (Random dot 2).

Discussion: In addition to being considered “a treat” compared to 4 hours daily patching, Eyetronix Flicker Glass therapy has improved visual acuity and stereopsis over what had been attained with conventional patching. This novel therapy holds promise in treating early post- surgical aphakic amblyopia by improving binocular vision, improving visual acuity, and being well- accepted during use.

86 Vision Development & Rehabilitation Volume 1, Issue 1 • April 2015 44th Annual Meeting Oral Papers and Posters

Poster Presentations, continued

Author: Angela To, OD Assistant Professor, Illinois College of Optometry

Title of Presentation: Idiopathic Intracranial Hypertension in a Teenager with a Complaint of Diplopia

Abstract Background: Pseudotumor cerebri or idiopathic­ intracranial hypertension (IIH) is a disease which presents as papilledema secondary to increased intracranial pressure, with a negative cranial MRI/V and increased opening pressure upon lumbar puncture. It occurs predominately in obese women of child-bearing age and may cause visual field and central visual acuity loss if the underlying cause is not addressed.

Case Summary: A 16 year old African American female presented with sudden onset diplopia, tinnitus and headaches. She was found to have a constant esotropia and hyper deviation that was not present at her last eye exam, one year prior. She also showed dramatic optic disc edema in both eyes. She was prescribed a fresnel prism for temporary, yet immediate, diplopia relief. After ordering a visual field, OCT and posterior pole photos, she was sent to a Neuro-ophthalmologist for a workup including lumbar puncture, MRV and MRI. She was diagnosed with IIH and placed on a regiment of Diamox. When she returned one month later, there was a significant decrease in swelling and her diplopia had disappeared.

Discussion: This case demonstrates the importance of striking a balance between relieving the patient’s symptoms while still ensuring that referrals are made to properly diagnose and manage the underlying condition. This patient was able to leave our office with single, clear, comfortable binocular vision while still understanding the severity of her condition. This case also shows that a careful optic nerve evaluation with imaging is warranted, despite being outside the expected demographic.

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Poster Presentations, continued

Author: Katherine Green Student, Illinois College of Optometry Class of 2015

Co-Author: Angela To, OD FAAO

Title of Presentation: Atypical Stargardt’s Disease in a Vision Therapy Patient

Abstract Background: Stargardt’s Disease is the number one inherited macular disorder among patients 10-20 years old, occurring in approximately 1 in 8,000 patients. This degenerative maculopathy is known for rapidly decreasing VAs to between 20/200-20/400, central visual field defects, and a characteristic fundus appearance of golden “fish tail” shaped flecks throughout the macula.

Case Summary: An 11 year old African American female was referred to the IEI Pediatrics and Binocular Vision department for a visual efficiancy exam. The patient was diagnosed with accomodative insufficiency, convergence insufficiency, and essential emmetropia. After completing two months of therapy, a cycloplegic exam was performed due to continued patient complaints of decreased vision at distance. Upon examining the posterior pole, the macula was found to contain bull’s eye maculopathy and pinpoint drusenoid-appearing disruptions concentrically around the fovea. Visual field testing revealed a central vision defect, and a clear disruption between the inner and outer segments of the macular photreceptors was seen on OCT. The patient was referred to a specialist in inherited retinal disorders and was diagnosed with atypical Stargardt’s degenerative maculopathy. Through continued vision therapy, the patient was able to obtain age appropriate accommodative skills and compensating vergence abilities. After two years of maintenance home vision therapy and regular follow-ups, the patient has maintained appropriate binocular vision skills, and the vision is stable.

Discussion: The present case shows the value of auxiliary testing in diagnosing retinal disorders, particularly those with atypical presentations. This case also highlights the importance of dilated fundus exams for all patients, even when referred in for therapy only. Finally, this case demonstrates the ability to use vision therapy to maximize the remaining vision in a patient with pathological vision loss.

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Author: Kelly Frantz, OD, FCOVD Professor, Illinois College of Optometry

Co-Author: Young Choi*, Trinh Doan*, Yi Pang, OD, PhD# Illinois College of Optometry (*student, #Faculty Member)

Title of Presentation: Successful Completion of Vision Therapy in Different Socioeconomic Backgrounds

Abstract Background: Previous studies have estab­lished a positive correlation between binocular vision dysfunctions and poor academic performance­ in school-aged children. Furthermore, many studies have reported the success of vision therapy (VT) in eliminating binocular disorders. However, we are unaware of any studies evaluating the success of VT in school-aged children based on socioeconomic status. The purpose of our study was to investigate successful completion of VT by school-aged children based on socioeconomic status.

Methods: Electronic health records of all children ages 6 years 0 months to 17 years 11 months who completed VT at the Illinois Eye Institute within the study specified 1-year period were reviewed. There were 163 of these children included in the study, who had been diagnosed with oculomotor, accommodative,­ and/or binocular dysfunctions (e.g., convergence insuf­ficiency and intermittent but not constant strabismus). For these children, method of payment for VT sessions was recorded as an indication of their socio­economic status. The children were classified either as having successfully completed VT or as having failed to complete VT due to noncompliance.

Results: There was no significant correlation between whether or not the child successfully completed VT and payment type (Medicaid versus self-pay/commercial insurance) (p=0.54). There also was no significant influence of gender of the children on success of VT (p=0.16). However, the older (ages 10-17 years) children were more likely to succeed in VT compared to the younger (ages 6-9 years) children (p = 0.03).

Discussion: Socioeconomic status indicated by payment type did not show an association with successfully completing VT for school-aged children in our clinic. Possible reasons for the older children having a greater VT completion rate include better understanding of procedures and ability to comply with home VT without parental assistance. Future studies could consider other variables such as household income to better predict socioeconomic status.

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Visit us at www.bernell.com to see our full line of products, which includes hundreds of items not found in our catalog! Note: Please ensure your Bernell online account is registered as a Healthcare Professional for full access to products and professional pricing. Email [email protected] for assistance. Consulting services customized to your specific needs: Practice Growth Case Presentation Professional Referrals Increase Case Acceptance Patient Communications Effectively Explain the Diagnosis Customized Brochures Empower Your Patients to Get the Care They Need Practice Newsletters VT Marketing Systems Practice Management Practice Growth Strategies Easy-to-Present CE Solutions to Staff Challenges Social Media Strategies Management Tools to Create the In-Office Digital Advertising Practice You’ve Always Wanted Schedule your Free Initial Consultation to learn how we might help you with your unique situation. Call 877.248.3823 or email Specializing in Vision Therapy Practice Management, 90 Marketing and Public Relations since 1988. [email protected] 2609 Honolulu Avenue, Suite 203, Montrose, California 91020 • Toll-free: 877.248.3823 • www.expansionconsultants.com Comprehensive Vision Therapy Software

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Streamline VT scheduling, session recording, Special COVD Pricing reporting, and billing with Nu Squared Vision Therapy Software.

Sign up for Nu Squared at the conference and save.

Attend our seminar for additional savings: Saturday, April 18, 7 a.m. in DaVinci 1.

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COVD PSAs Available in High Definition It is our goal to reach the individuals who are struggling needlessly with undiagnosed and untreated vision disorders that interfere with reading, learning, and other activities of daily living. Our HD PSAs cover a broad range of topics and are available in 30-second and 60-second prerecorded spots with captions available. Please join our campaign by donating to COVD and airing these PSAs on your radio station or sharing them through social media. • With a donation of $150.00 you can receive all 6 of our 30-second HD PSAs. • With a donation of $350.00 you can receive all 7 of our 60-second HD PSAs. • With a donation of $400.00 you can request ALL of our PSAs PLUS a DVD that plays the PSA videos on a loop to be used in waiting rooms and offices. Kaplan Estate Funds Speakers Bureau Program to Enhance the COVD Tour de Optometry Program

Over the years and in many types of optometric practices in the Washington, D.C. area - the Pentagon, managed care, and in private practice, Dr. Kaplan sought out continuing education. The one aspect of developing practice care that caught his attention and didn’t let go, was vision therapy. As a result of his exposure to the educational efforts of the College of Optometrists in Vision Development (COVD), other optometric associations, and individuals with vision care practices, Dr. Kaplan himself became a recognized practitioner of behavioral vision care.

Walter Kaplan, OD, FCOVD

Dr. Kaplan loved being a behavioral optometrist. When once asked about his hobbies beyond his work, he answered, "I have only two hobbies, learning more about vision therapy and my wife, not necessarily in that order."

COVD accepted a donation from the Kaplan Estate to support a speakers bureau of optometrists passionate about vision therapy (VT) and willing to spread the word to optometry students and residents, as an enhancement of our successful “Tour de Optometry” program.

"Dr. Kaplan was an active COVD Fellow member and we are honored that his family wanted to give back to the specialty that is in such great need of more private practice VT optometrists. There is a growing demand for VT and COVD is doing its best to increase the number of certified optometrists to fill the demand,” said President, Ida Chung, OD, FCOVD.

calendar of events

april 2015 COVD 45th Annual meeting April 14-18, 2015 The Bellagio Las Vegas, Nevada Event Information

2015 Spring Convention Arkansas Optometric Association April 23-26, 2015 The Peabody, Little Rock, Arkansas Vicki Farmer 24th Annual NORA Multi-Disciplinary 501/661-7675 Conference FAX: 501/372-0233 May 14-17, 2015 [email protected] Renaissance Denver Hotel www.arkansasoptometric.org Denver, Colorado Event Information MAY 2015 COVD Applied Concepts Course: June 2015 Vision Therapy 101 COVD Critical Concepts Course: Theory Tom Headline, COVT and Methods of Vision Therapy Part I May 12-13, 2015 Dr. Angela Peddle Manila, Philippines June 5-6, 2015 Event Information Calgary, Alberta, Canada Event Information IV International Congress SIODEC (International Society for JULY 2015 Developmental and Behavioral Global Summit on Innovations Optometry) in Health and Intellectual and May 14-17th, 2015 Developmental Disabilities (IDD) Palacio de Congresos de Gijón AADMD (American Academy of Gijón, Asturias, Spain Developmental Medicine and Dentistry) Event Information July 27-29, 2015 Registration Information Los Angeles, California Event Information

College of Optometrists in Vision Development 215 W. Garfield Road • Suite 200 • Aurora, OH 44202 330.995.0718 (voice) • 330.995.0719 (fax) [email protected] • www.covd.org