Binocularity Following Surgical Correction of Strabismus in Adults
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Strabismus Surgery Kenneth W
11 Strabismus Surgery Kenneth W. Wright and Pauline Hong his chapter discusses various strabismus surgery procedures Tand how they work. When a muscle contracts, it produces a force that rotates the globe. The rotational force that moves an eye is directly proportional to the length of the moment arm (m) (Fig. 11-1A) and the force of the muscle contraction (F) (Fig. 11-1B). Rotational force ϭ m ϫ F where m ϭ moment arm and F ϭ muscle force. Strabismus surgery corrects ocular misalignment by at least four different mechanisms: slackening a muscle (i.e., recession), tightening a muscle (i.e., resection or plication), reducing the length of the moment arm (i.e., Faden), or changing the vector of the muscle force by moving the muscle’s insertion site (i.e., transposition). MUSCLE RECESSION A muscle recession moves the muscle insertion closer to the muscle’s origin (Fig. 11-2), creating muscle slack. This muscle slack reduces muscle strength per Starling’s length–tension curve but does not significantly change the moment arm when the eye is in primary position (Fig. 11-3). The arc of contact of the rectus muscles wrapping around the globe to insert anterior to the equator of the eye allows for large recessions of the rectus muscles without significantly changing the moment arm. Figure 11-3 shows a 7.0-mm recession of the medial and lateral rectus muscles. Note there is no change in the moment arm with these large recessions. Thus, the effect of a recession on eye position is determined by the amount of muscle slack created.1a The 388 chapter 11: strabismus surgery 389 FIGURE 11-1A,B. -
Binocular Vision
Continuing education CET Binocular vision Part 5 – Binocular sensory status and miscellaneous tests In the latest addition to our occasional series on the assessment and management of binocular vision in practice, Priya Dabasia looks at sensory status and its measurement. Module C16058, one general CET point for optometrists and dispensing opticians he preceding accounts in ● Confusion – the superimposition this mini series of binocular of two dissimilar images in higher vision (BV) testing have processing, experienced predominantly detailed procedures for on observing complex scenes such as ‘a the cover test (CT), ocular room’. The same patient is more likely motility and heterophoria to report diplopia on viewing a small, Tcompensation. The final two articles bright target such as a penlight aim to outline the assessment of ● Retinal rivalry – the observation binocular sensory status, stereopsis and of alternating percepts or a combined convergence. ‘mosaic’ so that images from each eye Having two frontally positioned eyes are never seen simultaneously. separated by approximately 65mm enhances many aspects of our visual Anomalous retinal correspondence performance – a wide panorama, (ARC) is considered a more efficient higher acuity, and three-dimensional sensory adaptation to heterotropia as perception to a distance of 200 metres, suppression occurs in localised zones provided both eyes are fully functional Figure 1 to the fovea of one eye corresponds to a rather than spanning the binocular and coordinated together. Anomalies Worth 4-Dot point temporal to the fovea in the other field. It facilitates a weaker form of of binocular function have often been test eye. In reality, BSV can still be achieved BSV, relieving diplopia while enabling described as ‘the hidden learning with misaligned visual axes provided a good level of depth perception of up disability’ as they impair academic the disparity occurs within the limits of to 100’’. -
A Patient & Parent Guide to Strabismus Surgery
A Patient & Parent Guide to Strabismus Surgery By George R. Beauchamp, M.D. Paul R. Mitchell, M.D. Table of Contents: Part I: Background Information 1. Basic Anatomy and Functions of the Extra-ocular Muscles 2. What is Strabismus? 3. What Causes Strabismus? 4. What are the Signs and Symptoms of Strabismus? 5. Why is Strabismus Surgery Performed? Part II: Making a Decision 6. What are the Options in Strabismus Treatment? 7. The Preoperative Consultation 8. Choosing Your Surgeon 9. Risks, Benefits, Limitations and Alternatives to Surgery 10. How is Strabismus Surgery Performed? 11. Timing of Surgery Part III: What to Expect Around the Time of Surgery 12. Before Surgery 13. During Surgery 14. After Surgery 15. What are the Potential Complications? 16. Myths About Strabismus Surgery Part IV: Additional Matters to Consider 17. About Children and Strabismus Surgery 18. About Adults and Strabismus Surgery 19. Why if May be Important to a Person to Have Strabismus Surgery (and How Much) Part V: A Parent’s Perspective on Strabismus Surgery 20. My Son’s Diagnosis and Treatment 21. Growing Up with Strabismus 22. Increasing Signs that Surgery Was Needed 23. Making the Decision to Proceed with Surgery 24. Explaining Eye Surgery to My Son 25. After Surgery Appendix Part I: Background Information Chapter 1: Basic Anatomy and Actions of the Extra-ocular Muscles The muscles that move the eye are called the extra-ocular muscles. There are six of them on each eye. They work together in pairs—complementary (or yoke) muscles pulling the eyes in the same direction(s), and opposites (or antagonists) pulling the eyes in opposite directions. -
Worth 4 Dot App for Determining Size and Depth of Suppression
Article Worth 4 Dot App for Determining Size and Depth of Suppression Ann L. Webber1, Thomas R. Mandall1, Darcy T. Molloy1, Lucas J. Lister1, and Eileen E. Birch2,3 1 School of Optometry and Vision Science, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia 2 Retina Foundation of the Southwest, Dallas, TX, USA 3 UT Southwestern Medical Center, Dallas, TX, USA Correspondence: Ann L. Webber, Purpose: To describe and evaluate an iOS application suppression test, Worth 4 Dot Queensland University of App (W4DApp), which was designed and developed to assess size and depth of Technology, 60 Musk Avenue, Kelvin suppression. Grove, Queensland 4059, Australia. Methods: e-mail: [email protected] Characteristics of sensory fusion were evaluated in 25 participants (age 12– 69 years) with normal (n = 6) and abnormal (n = 19) binocular vision. Suppression zone Received: August 12, 2019 size and classification of fusion were determined by W4DApp and by flashlight Worth4 Accepted: December 13, 2019 Dot (W4D) responses from 33 cm to 6 m. Measures of suppression depth were compared Published: March 9, 2020 between the W4DApp, the flashlight W4D with neutral density filter bar and the dichop- Keywords: suppression; binocular tic letters contrast balance index test. vision; Worth 4 Dot Results: There was high agreement in classification of fusion between the W4DApp Citation: Webber AL, Mandall TR, method and that derived from flashlight W4D responses from 33 cm to 6m(α = Molloy DT, Lister LJ, Birch EE. Worth 0.817). There were no significant differences in success rates or in reliability between 4 Dot App for determining size and the W4DApp or the flashlight W4D methods for determining suppression zone size. -
Binocular Vision
BINOCULAR VISION Rahul Bhola, MD Pediatric Ophthalmology Fellow The University of Iowa Department of Ophthalmology & Visual Sciences posted Jan. 18, 2006, updated Jan. 23, 2006 Binocular vision is one of the hallmarks of the human race that has bestowed on it the supremacy in the hierarchy of the animal kingdom. It is an asset with normal alignment of the two eyes, but becomes a liability when the alignment is lost. Binocular Single Vision may be defined as the state of simultaneous vision, which is achieved by the coordinated use of both eyes, so that separate and slightly dissimilar images arising in each eye are appreciated as a single image by the process of fusion. Thus binocular vision implies fusion, the blending of sight from the two eyes to form a single percept. Binocular Single Vision can be: 1. Normal – Binocular Single vision can be classified as normal when it is bifoveal and there is no manifest deviation. 2. Anomalous - Binocular Single vision is anomalous when the images of the fixated object are projected from the fovea of one eye and an extrafoveal area of the other eye i.e. when the visual direction of the retinal elements has changed. A small manifest strabismus is therefore always present in anomalous Binocular Single vision. Normal Binocular Single vision requires: 1. Clear Visual Axis leading to a reasonably clear vision in both eyes 2. The ability of the retino-cortical elements to function in association with each other to promote the fusion of two slightly dissimilar images i.e. Sensory fusion. 3. The precise co-ordination of the two eyes for all direction of gazes, so that corresponding retino-cortical element are placed in a position to deal with two images i.e. -
Consecutive Exotropia After Convergent Strabismus Surgery—Surgical Treatment
Open Journal of Ophthalmology, 2016, 6, 103-107 Published Online May 2016 in SciRes. http://www.scirp.org/journal/ojoph http://dx.doi.org/10.4236/ojoph.2016.62014 Consecutive Exotropia after Convergent Strabismus Surgery—Surgical Treatment Ala Paduca State University of Medicine and Pharmacy “Nicolae Testemitanu”, Chișinău, Moldova Received 19 March 2016; accepted 9 May 2016; published 12 May 2016 Copyright © 2016 by author and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Purpose: In this study the results of consecutive exotropia surgical treatment by using different surgical technics are presented. Methods: This study included 34 patients, aged 21 to 47 years (mean 27.9), who underwent medial rectus muscle advancement alone or in combination with medial rectus resection and/or lateral rectus recession. The mean interval between original sur- gery and surgery for consecutive exotropia was 8.5 years (range: 5.5 years to 14 years). Most of patients had 2 and more prior surgeries (73.5%) sold by an adduction deficit (47.06%). Results: The overall mean preoperative exodeviation was 35.12 ± 10.13 PD. Satisfactory alignment (within 10 PD of orthophoria) was achieved in 20 patients (58.8%) at 10 days after surgery and 24 pa- tients (70.5%) at final 6-month follow-up. The most common surgical procedures were unilateral MR advancement and LR recession—47%. Conclusion: Medial rectus advancement is an effective method of surgical treatment, especially in cases with adduction limitation, but the risk of the eye- lid fissure narrowing in cases of MRM advancement more than 5 mm associated with resection is present. -
Strabismus: a Decision Making Approach
Strabismus A Decision Making Approach Gunter K. von Noorden, M.D. Eugene M. Helveston, M.D. Strabismus: A Decision Making Approach Gunter K. von Noorden, M.D. Emeritus Professor of Ophthalmology and Pediatrics Baylor College of Medicine Houston, Texas Eugene M. Helveston, M.D. Emeritus Professor of Ophthalmology Indiana University School of Medicine Indianapolis, Indiana Published originally in English under the title: Strabismus: A Decision Making Approach. By Gunter K. von Noorden and Eugene M. Helveston Published in 1994 by Mosby-Year Book, Inc., St. Louis, MO Copyright held by Gunter K. von Noorden and Eugene M. Helveston All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the authors. Copyright © 2010 Table of Contents Foreword Preface 1.01 Equipment for Examination of the Patient with Strabismus 1.02 History 1.03 Inspection of Patient 1.04 Sequence of Motility Examination 1.05 Does This Baby See? 1.06 Visual Acuity – Methods of Examination 1.07 Visual Acuity Testing in Infants 1.08 Primary versus Secondary Deviation 1.09 Evaluation of Monocular Movements – Ductions 1.10 Evaluation of Binocular Movements – Versions 1.11 Unilaterally Reduced Vision Associated with Orthotropia 1.12 Unilateral Decrease of Visual Acuity Associated with Heterotropia 1.13 Decentered Corneal Light Reflex 1.14 Strabismus – Generic Classification 1.15 Is Latent Strabismus -
Your Source Vision
Good-Lite Product Catalog YOUR SOURCE for VISION Cognitive Test • Grating Acuity • Wall Charts • Handheld Charts • EyeSpy 20/20 • 10x18 Charts • ETDRS Charts • Low Vision • Intermediate Vision • Near Vision • Read- ing Cards • ETDRS Cabinet • Spot Vision Screener • ESV1200 - 9x14 • ESV1018 - 10x18 • Insta-Line • CSV-1000 • Super Pinhole • Accessories • Screening Software • Testing Software • Fixation • Occluders • Fun Frames • Prisms • Hyperopia • Retinoscopy • Eye Models • Stereo Test • Worth 4-Dot • Color Books & Tests • D15 Style Color Test • Desaturated 1-800-263-3557 Color Test • Projector Slides • Continuous Text • Adult Charts • Children Charts • Pediatric Charts • Vectographic Slides • Amsler Grid • Campimeter • Prism Bar • Loose Prism • Spanish • Vectograph • Maddox • Cylinders • Phoropter • Trial Lens/Frames • Filters • Risley • Eye PatchesGOOD-LITE • LEA Symbols • LEA Numbers • Contrast Sensitivity • Visual Field • Cognitive Vision • Adaptation • Color Vision • Optokinetic • Tangent Screen • Flat & Curved Prism • Magnifier • Flipper • Slit Lamp Celebrating More Than 80 Years of Good-Lite The Good-Lite Company is celebrating In the 1970s, Palmer worked with Otto in children and adults with developmental more than 80 years as the industry leader Lippmann, MD, to develop HOTV optotypes delays/disabilities. The American Academy of in illuminated cabinets; evidence-based eye using Sloan letters. Lippmann’s HOTV Pediatrics, et al., includes LEA Symbols on its charts, such as the LEA Symbols, and many optotypes — a modified version of a Stycar list of recommended tests for preschool vision more vision screening and testing products matching letters test based on Snellen screening. available in this catalog and online. letters — are useful for screening and testing Good-Lite values its key role in helping vision The combined efforts of Robert Good, vision of children as young as age 3 years. -
The Role of Stereopsis and Binocular Fusion in Surgical Treatment Of
per m Ex i en & ta l l a O ic p in l h Journal of Clinical & Experimental t C h f a o l m l a o Ruiz et al., J Clin Exp Opthamol 2018, 9:4 n l o r g u o y Ophthalmology J DOI: 10.4172/2155-9570.1000742 ISSN: 2155-9570 Research Article Open Access The Role of Stereopsis and Binocular Fusion in Surgical Treatment of Intermittent Exotropia Maria Cristina Fernandez-Ruiz1, John Lillvis2, Conrad L Giles3,4, Rajesh Rao3,4,5, Leemor B Rotberg3,4,5, Lisa Bohra3,4,5, John D Roarty3,4,5, Elena M Gianfermi3,4 and Reecha Sachdeva Bahl3,4* 1Department of Ophthalmology, Baylor College of Medicine, USA 2Department of Ophthalmology, University at Buffalo School of Medicine and Biomedical Sciences, USA 3Department of Ophthalmology, Wayne State University School of Medicine, USA 4Department of Ophthalmology, Children’s Hospital of Michigan, USA 5Department of Ophthalmology, Oakland University William Beaumont School of Medicine, USA *Corresponding author: Reecha S Bahl, Department of Ophthalmology, Kresge Eye Institute, 4717 St Antoine, Detroit, Michigan, USA, Tel: +1 2166597354; E-mail: [email protected] Received date: July 06, 2018; Accepted date: July 16, 2018; Published date: July 25, 2018 Copyright: ©2018 Fernandez Ruiz MC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Background/Aims: The purpose of this study is to identify the appropriate timing for surgical treatment of intermittent exotropia (XT) in the pediatric population by examining several parameters that may contribute to surgical planning. -
Quantification of Stereopsis in Patients with Impaired Binocularity
1040-5488/16/9306-0588/0 VOL. 93, NO. 6, PP. 588Y593 OPTOMETRY AND VISION SCIENCE Copyright * 2016 American Academy of Optometry ORIGINAL ARTICLE Quantification of Stereopsis in Patients with Impaired Binocularity Sang Beom Han*, Hee Kyung Yang*, Jonghyun Kim†, Keehoon Hong‡, Byoungho Lee‡, and Jeong-Min Hwang* ABSTRACT Purpose. To quantify stereopsis at distance resulting from binocular fusion in patients with impaired binocular vision using a three-dimensional (3-D) display stereotest. Methods. A total of 68 patients (age range, 6 to 85 years) with strabismus (40 esotropes and 28 exotropes) whose stereoacuity could not be measured with the near and distance Randot stereotests were included. Contour-based circles with a wide range of crossed horizontal disparities (2500 to 20 arcsec) displayed on a 3-D monitor were presented to subjects at 3 m. Between the patients who had stereoacuity of at least 2500 arcsec and those with no measurable stereoacuity, parameters including age, sex, best-corrected visual acuity, spherical equivalent refractive error, Worth 4 dot test results, and type and angle of deviation were compared. Results. Stereoacuity at distance of 2500 arcsec or better was detected in 25 (63%) of 40 esotropes, and 16 (57%) of 28 exotropes, although stereoacuity of 800 arcsec or better was found only in two (5%) esotropes and one (4%) exotrope. Patients with stereopsis were significantly younger (19.3 T 16.9 years) than those with no measurable stereopsis (31.5 T 26.4 years) (p = 0.040). There were no significant differences in best-corrected visual acuity, presence of amblyopia 920/100, spherical equivalent refractive error, type of deviation, deviation angle, sex, and Worth 4 dot test results between these groups. -
Improvement of Binocular Summation in Intermittent Exotropia Following Successful Postoperative Alignment Yueping Li*, Juan Ding & Wei Zhang
www.nature.com/scientificreports OPEN Improvement of binocular summation in intermittent exotropia following successful postoperative alignment YuePing Li*, Juan Ding & Wei Zhang To investigate the improvement of binocular summation (BiS) at high contrast (100%) and diferent low contrasts (10, 5 and 2.5%) in patients with intermittent exotropia (IXT) after successfully postoperative alignment. A total of 76 patients (aged 9–40 years) with IXT and poor control at distance before surgery were enrolled in this study. The postoperative deviations ranged between 4 PD esophoria to 10 PD exotropia in the primary position (at near and at distance) in all the enrolled patients. The follow-up visits were 2–3 months after the surgery. We analyzed preoperative and postoperative BiS and the proportions of patients with diferent BiS for the high contrast and the low contrasts. Binocular summation (BiS) was classifed into three situations: binocular summation, equal and inbibition. The results of the distant random dots stereograph (RDS) were grouped into A, unable to recognize; B, moderate, 200″ ≤ RDS ≤ 400″ and C, good, RDS < 200″. Following the successful postoperative alignment, the proportion of patients with BiS were increased from 9.2 to 40.8%, 17.1 to 53.9%, 21.1 to 76.1% and 21.1 to 72.4% at 100%, 10%, 5% and 2.5% contrasts respectively. At 2.5% contrast, (1) more patients presented binocular summation in the groups B and C; (2) postoperative improvements of binocular visual acuity (BVA) in groups B (1.5 ± 1.03 lines) and C (1.57 ± 1.26 lines) were signifcantly diferent from the BVA in the group A (0.74 ± 1.00 line); and (3) in the group with central fusion, more patients presented BiS after surgery and the postoperative BVA improved by 1.43 ± 1.16 lines. -
Surgical Management of Small Angle Strabismus Dr V
Short Review Surgical management of small angle strabismus Dr V. Akila Ramkumar and Dr Ketaki S. Subhedar Department of Pediatric Small angle deviation refers to deviations <15 to expose the tendon and making successive small Ophthalmology, Sankara prism diopters (PD). Standard rectus muscle reces- cuts in the rectus muscle at the insertion until the Nethralaya, Chennai, India sion–resection is designed to correct moderate to desired effect is achieved. Over half the tendon large angle strabismus >10 PD. Small angle eso- was removed starting at one pole, leaving one Correspondence: deviations and vertical deviations cause astheno- tendon pole attached to sclera, resulting in the cut Dr V. Akila Ramakumar, pic symptoms and diplopia which may be frustrat- tendon slanting back at an angle of 45°. A 60– Associate Consultant, Paediatric ing for the patient and surgeons alike. This can be 70% tenotomy, or removing 6–7 mm of tendon, Ophthalmology and Strabismus. true for primary deviations and unfortunately corrects ∼4Δ of strabismus. Email: [email protected] even in postoperative patients. Several non- The slanted tenotomy works by effectively surgical management options to overcome the moving the insertion, thus changing the vector of diplopia include prisms, botuliniuminjections, muscle force and potentially inducing incomi- Bangarters filters and the last resort of self-guided tance. A vertical deviation could be induced if an coping mechanism. If these fail or any of these upper tenotomy of one medial rectus muscle was are non-desirable, then the alternative solution performed along with a lower tenotomy on the would be the surgical intervention. Unfortunately, contralateral medial rectus muscle.