Association Between Visual Field Damage and Corneal Structural
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GUIDE for the Evaluation of VISUAL Impairment
International Society for Low vision Research and Rehabilitation GUIDE for the Evaluation of VISUAL Impairment Published through the Pacific Vision Foundation, San Francisco for presentation at the International Low Vision Conference VISION-99. TABLE of CONTENTS INTRODUCTION 1 PART 1 – OVERVIEW 3 Aspects of Vision Loss 3 Visual Functions 4 Functional Vision 4 Use of Scales 5 Ability Profiles 5 PART 2 – ASSESSMENT OF VISUAL FUNCTIONS 6 Visual Acuity Assessment 6 In the Normal and Near-normal range 6 In the Low Vision range 8 Reading Acuity vs. Letter Chart Acuity 10 Visual Field Assessment 11 Monocular vs. Binocular Fields 12 PART 3 – ESTIMATING FUNCTIONAL VISION 13 A General Ability Scale 13 Visual Acuity Scores, Visual Field Scores 15 Calculation Rules 18 Functional Vision Score, Adjustments 20 Examples 22 PART 4 – DIRECT ASSESSMENT OF FUNCTIONAL VISION 24 Vision-related Activities 24 Creating an Activity Profile 25 Participation 27 PART 5 – DISCUSSION AND BACKGROUND 28 Comparison to AMA scales 28 Statistical Use of the Visual Acuity Score 30 Comparison to ICIDH-2 31 Bibliography 31 © Copyright 1999 by August Colenbrander, M.D. All rights reserved. GUIDE for the Evaluation of VISUAL Impairment Summer 1999 INTRODUCTION OBJECTIVE Measurement Guidelines for Collaborative Studies of the National Eye Institute (NEI), This GUIDE presents a coordinated system for the Bethesda, MD evaluation of the functional aspects of vision. It has been prepared on behalf of the International WORK GROUP Society for Low Vision Research and Rehabilitation (ISLRR) for presentation at The GUIDE was approved by a Work Group VISION-99, the fifth International Low Vision including the following members: conference. -
425-428 YOSHI:Shoja
European Journal of Ophthalmology / Vol. 19 no. 3, 2009 / pp. 425-428 Effects of astigmatism on the Humphrey Matrix perimeter TOSHIAKI YOSHII, TOYOAKI MATSUURA, EIICHI YUKAWA, YOSHIAKI HARA Department of Ophthalmology, Nara Medical University, Nara - Japan PURPOSE. To evaluate the influence of astigmatism in terms of its amount and direction on the results of Humphrey Matrix perimetry. METHODS. A total of 31 healthy volunteers from hospital staff were consecutively recruited to undergo repeat testing with Humphrey Matrix 24-2 full threshold program with various induced simple myopic astigmatism. All subjects had previous experience (at least twice) with Matrix testing. To produce simple myopic astigmatism, a 0 diopter (D), +1 D, or +2 D cylindrical lens was added and inserted in the 180° direction and in the 90° direction after complete correction of distance vision. The influences of astigmatism were evaluated in terms of the mean deviation (MD), pattern standard deviation (PSD), and test duration (TD). RESULTS. A significant difference was observed only in the MD from five sessions. The MD in cases of 2 D inverse astigmatism was significantly lower than that in the absence of astig- matism. CONCLUSIONS. In patients with inverse myopic astigmatism of ≥ 2 D, the influences of astig- matism on the visual field should be taken into consideration when the results of Humphrey Matrix perimetry are evaluated. (Eur J Ophthalmol 2009; 19: 425-8) KEY WORDS. Astigmatism, Frequency doubling technology, FDT Matrix, Perimetry Accepted: October 10, 2008 INTRODUCTION as an FDT perimeter and became commercially available. In this perimeter, the examination time was shortened due Refractive error is one of the factors affecting the results to changes in the algorithm, the target size was made of perimetry. -
ICO Guidelines for Glaucoma Eye Care
ICO Guidelines for Glaucoma Eye Care International Council of Ophthalmology Guidelines for Glaucoma Eye Care The International Council of Ophthalmology (ICO) Guidelines for Glaucoma Eye Care have been developed as a supportive and educational resource for ophthalmologists and eye care providers worldwide. The goal is to improve the quality of eye care for patients and to reduce the risk of vision loss from the most common forms of open and closed angle glaucoma around the world. Core requirements for the appropriate care of open and closed angle glaucoma have been summarized, and consider low and intermediate to high resource settings. This is the first edition of the ICO Guidelines for Glaucoma Eye Care (February 2016). They are designed to be a working document to be adapted for local use, and we hope that the Guidelines are easy to read and translate. 2015 Task Force for Glaucoma Eye Care Neeru Gupta, MD, PhD, MBA, Chairman Tin Aung, MBBS, PhD Nathan Congdon, MD Tanuj Dada, MD Fabian Lerner, MD Sola Olawoye, MD Serge Resnikoff, MD, PhD Ningli Wang, MD, PhD Richard Wormald, MD Acknowledgements We gratefully acknowledge Dr. Ivo Kocur, Medical Officer, Prevention of Blindness, World Health Organization (WHO), Geneva, Switzerland, for his invaluable input and participation in the discussions of the Task Force. We sincerely thank Professor Hugh Taylor, ICO President, Melbourne, Australia, for many helpful insights during the development of these Guidelines. International Council of Ophthalmology | Guidelines for Glaucoma Eye Care International -
Iol Calculations for Patients with Keratoconus
s THE LITERATURE IOL CALCULATIONS FOR PATIENTS WITH KERATOCONUS Work continues to improve refractive accuracy in this patient population. BY ALICE ROTHWELL, MBCHB, AND ANDREW M.J. TURNBULL, BM, PGCERTMEDED, PGDIPCRS, FRCOPHTH INTRAOCULAR LENS POWER CALCULATION TABLE 1. CLASSIFICATION OF KERATOCONUS SEVERITY IN EYES WITH KERATOCONUS Stage Keratometry Reading Savini G, Abbate R, Hoffer KJ, et al1 1 ≤ 48.00 D Industry support: K.J.H. licenses 2 > 48.00 D registered trademark name Hoffer to various companies 3 > 53.00 D ABSTRACT SUMMARY spherical equivalent. Myopic and stage 1 disease. Accuracy decreased Savini and colleagues compared hyperopic surprises were indicated by with more advanced keratoconus, with the prediction errors (PEs) of negative and positive PEs, respectively. a MedAE of greater than 2.50 D in all five standard formulas: Barrett Mean error (ME), median absolute stage 3 eyes. Universal II (BUII), Haigis, Hoffer Q, error (MedAE), mean absolute error, Holladay 1, and SRK/T. The study and percentage of eyes achieving within DISCUSSION included 41 consecutive keratoconic ±0.50 D, ±0.75 D, and ±1.00 D of the Keratoconus presents multiple eyes undergoing phacoemulsification refractive target were also calculated. challenges to IOL selection. First, and IOL implantation. Eyes were A hyperopic ME was found across all the standard keratometric index classified by disease severity (Table 1). five formulas. Across the whole dataset, cannot reliably be applied to these A subjective refraction was obtained the lowest ME (0.91 D) and MedAE eyes because this index depends on for each eye at 1 month postoperatively. (0.62 D) and the highest percentage a normal ratio between the anterior The PE for each eye was calculated by (36%) of eyes within ±0.50 D of target and posterior corneal surfaces, but subtracting the predicted spherical were achieved with the SRK/T formula. -
Presbyopia and Glaucoma: Two Diseases, One Pathophysiology? the 2017 Friedenwald Lecture
Lecture Presbyopia and Glaucoma: Two Diseases, One Pathophysiology? The 2017 Friedenwald Lecture Paul L. Kaufman,1 Elke Lutjen¨ Drecoll,2 and Mary Ann Croft1 1Department of Ophthalmology and Visual Sciences, Wisconsin National Primate Research Center, McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States 2Institute of Anatomy II, Erlangen, Germany Correspondence: Paul L. Kaufman, Department of Ophthalmology and Visual Sciences, University of Wisconsin Clinical Sciences Center, 600 Highland Avenue, Madison, WI 53792-3220, USA; [email protected]. Citation: Kaufman PL, Lutjen¨ Drecoll E, Croft MA. Presbyopia and glaucoma: two diseases, one pathophysiology? The 2017 Friedenwald Lecture. Invest Ophthalmol Vis Sci. 2019;60:1801–1812. https://doi.org/10.1167/iovs.19-26899 resbyopia, the progressive loss of near focus as we age, is choroid and the retina stretch in parallel with each other during P the world’s most prevalent ocular affliction. Accommoda- the accommodative response. The question remains how far tive amplitude is at its maximum (~15 diopters) in the teen back the accommodative choroid/retina movement goes. years and declines fairly linearly thereafter (Fig. 1).1 By age 25 By ‘‘marking’’ points on retinal photographs (e.g., vascular about half the maximum accommodative amplitude has been bifurcations) in aphakic (to avoid lens magnification artifacts lost, by age 35 two-thirds are gone, and by the mid-40s all is during accommodation) monkey eyes, movement of the retina gone. Clinical symptoms usually begin at age ~40. The during accommodation can be quantified in terms of both accommodative apparatus of the rhesus monkey is very similar direction and magnitude (Fig. -
Analysis of Human Corneal Igg by Isoelectric Focusing
Investigative Ophthalmology & Visual Science, Vol. 29, No. 10, October 1988 Copyright © Association for Research in Vision and Ophthalmology Analysis of Human Corneal IgG by Isoelectric Focusing J. Clifford Woldrep,* Robin L. Noe,f and R. Doyle Stulringf Parameters which regulate the localization and retention of IgG within the corneal stroma are complex and poorly understood. Although multiple factors are involved, electrostatic interactions between IgG and anionic corneal tissue components, ie, proteoglycans (PG) and glycosaminoglycans (GAG) may regulate the distribution of antibodies within the corneal stroma. Isoelectric focusing (IEF) and blotting analysis of IgG revealed a restricted pi profile for both central and peripheral regions of the normal cornea. Similar analysis of pathological corneas from keratoplasty specimens in Fuchs' dys- trophy and keratoconus reveal a variable IEF profile. In the majority of keratoplasty specimens from patients with corneal edema or graft rejection, there was generally little or no IgG detectable. These results suggest that in edematous corneas where there is altered PG/GAG in the stroma and modified fluid dynamics, there is a concomitant loss of IgG. These findings may have implications for immuno- logic surveillance and protection of the avascular cornea. Invest Ophthalmol Vis Sci 29:1538-1543, 1988 The humoral immune system plays an important the soluble plasma proteins through ionic interac- role in mediating immunologic surveillance and pro- tions. The PGs and GAGs have long been known to -
Cataract Surgery & Glaucoma
worldclasslasik.com http://www.worldclasslasik.com/cataract-surgery-new-jersey/cataract-surgery-glaucoma/ Cataract Surgery & Glaucoma The lens of your eye is responsible for focusing light on the objects you see. If the lens is clouded, then you can’t see things clearly, and this is known as a cataract. It can form gradually over many years or you can be born with a cataract. For some people, cataracts are not even noticeable. They just find themselves turning on more lights to read or having trouble with glares while driving at night. Most cataracts are problematic later in life. It is estimated that more than half of all Americans over the age of 80 will have cataracts or have had them corrected with surgery. Another common eye problem for seniors is glaucoma. Glaucoma is actually a group of eye diseases that affect the optic nerve by causing various types of damage due to high pressure. The optic nerve carries images from the retina to the brain, so advanced glaucoma can actually impair vision to the point of blindness. It is actually the leading cause of blindness in the world. However, glaucoma can be remedied in a number of ways. Early detection and treatment by your eye surgeon are critical in achieving optimal results. Resolve Cataracts and Glaucoma with Surgery While many adults over the age of 65 suffer from both cataracts and glaucoma, it is important to note that the two are not related. Glaucoma does not cause cataracts and cataracts do not cause glaucoma. That being said, cataract surgery involves creating a small incision in the lens of the eye to remove the affected, or “cloudy” area of the lens. -
Bass – Glaucomatous-Type Field Loss Not Due to Glaucoma
Glaucoma on the Brain! Glaucomatous-Type Yes, we see lots of glaucoma Field Loss Not Due to Not every field that looks like glaucoma is due to glaucoma! Glaucoma If you misdiagnose glaucoma, you could miss other sight-threatening and life-threatening Sherry J. Bass, OD, FAAO disorders SUNY College of Optometry New York, NY Types of Glaucomatous Visual Field Defects Paracentral Defects Nasal Step Defects Arcuate and Bjerrum Defects Altitudinal Defects Peripheral Field Constriction to Tunnel Fields 1 Visual Field Defects in Very Early Glaucoma Paracentral loss Early superior/inferior temporal RNFL and rim loss: short axons Arcuate defects above or below the papillomacular bundle Arcuate field loss in the nasal field close to fixation Superotemporal notch Visual Field Defects in Early Glaucoma Nasal step More widespread RNFL loss and rim loss in the inferior or superior temporal rim tissue : longer axons Loss stops abruptly at the horizontal raphae “Step” pattern 2 Visual Field Defects in Moderate Glaucoma Arcuate scotoma- Bjerrum scotoma Focal notches in the inferior and/or superior rim tissue that reach the edge of the disc Denser field defects Follow an arcuate pattern connected to the blind spot 3 Visual Field Defects in Advanced Glaucoma End-Stage Glaucoma Dense Altitudinal Loss Progressive loss of superior or inferior rim tissue Non-Glaucomatous Etiology of End-Stage Glaucoma Paracentral Field Loss Peripheral constriction Hereditary macular Loss of temporal rim tissue diseases Temporal “islands” Stargardt’s macular due -
Visual Pathways
Visual Pathways Michael Davidson Professor, Ophthalmology Diplomate, American College of Veterinary Ophthalmologists Department of Clinical Sciences College of Veterinary Medicine North Carolina State University Raleigh, North Carolina, USA <[email protected]> Vision in Animals Miller PE, Murphy CJ. Vision in Dogs. JAVMA. 1995; 207: 1623. Miller PE, Murphy CJ. Equine Vision. In Equine Ophthalmology ed. Gilger BC. 2nd ed. 2011: pp 398- 433. Ofri R. Optics and Physiology of Vision. In Veterinary Ophthalmology. ed. Gelatt KN 5th ed. 2013: 208-270, Visual Pathways, Responses and Reflexes: Relevant Structures Optic n (CN II) – somatic afferent Oculomotor n (CN III), Trochlear n (CN IV), Abducens n (CN VI) – somatic efferent to extraocular muscles Facial n (CN VII)– visceral efferent to eyelids Rostral colliculi – brainstem center that mediates somatic reflexes in response to visual stimuli Cerebellum Cerebro-cortex esp. occipital lobe www.studyblue.com Visual Pathway Visual Cortex Optic Radiation Lateral Geniculate Body www.studyblue.com Visual Field each cerebral hemisphere receives information from contralateral visual field (“the area that can be seen when the eye is directed forward”) visual field Visual Fiber (Retinotopic) Segregation nasal retinal fibers decussate at chiasm, temporal retinal fibers remain ipsilateral Nasal Temporal Retina Retina Fibers Fibers Decussate Remain Ipsilateral OD Visual Field OS Total visual field OD temporal nasal hemifield hemifield temporal nasal fibers fibers Nasal Temporal Retina = Retina = Temporal -
Management Modalities for Keratoconus an Overview of Noninterventional and Interventional Treatments
REFRACTIVE SURGERY FEATURE STORY EXCLUSIVE ONLINE CONTENT AVAILABLE Management Modalities for Keratoconus An overview of noninterventional and interventional treatments. BY MAZEN M. SINJAB, MD, PHD anagement of keratoconus has advanced TAKE-HOME MESSAGE during the past few years, and surgeons can • When evaluating patients with keratoconus, ask now choose among numerous traditional and them to stop using RGP contact lenses at least 2 modern treatments. Traditional modalities weeks before evaluation to achieve correct Msuch as spectacle correction, contact lenses, penetrating measurement of the corneal shape. keratoplasty (PKP), and conductive keratoplasty (CK) • Interventional management modalities include CK, are still effective; however, demand for the last two has PKP, DALK, ICRSs, CXL, phakic IOLs, or some decreased with the advent of modern alternatives, specifi- combination of these treatments. cally intrastromal corneal ring segments (ICRSs) and cor- • Making the right management decision depends neal collagen crosslinking (CXL). Caution should be used on the patient’s corneal transparency and stress when considering these newer treatment modalities, and lines, age, progression, contact lens tolerance, surgeons should be aware of their indications, contraindi- refractive error, UCVA and BCVA, K-max, corneal cations, conditions, and complications before proceeding thickness, and sex. with treatment. Keratoconus treatments can be divided into two cate- Some patients achieve good vision correction and comfort gories, interventional and noninterventional. In this article, with this strategy. particular attention is given to ICRSs and CXL, as they are Advances in lens designs and materials have increased the the most popular emerging interventional management proportion of keratoconus patients who can be fitted with modalities for keratoconus. -
Visual Field Defects Essentials for Neurologists
J Neurol (2003) 250:407–411 DOI 10.1007/s00415-003-1069-1 REVIEW Ulrich Schiefer Visual field defects Essentials for neurologists Introduction I The visual pathway – a highly sensitive “functional trip-wire” The visual pathway achieves neuronal signal transduc- tion between retinal photoreceptors, visual cortex and higher order visual areas. Lesions affecting this “trip- wire” will result in visual impairment which should in- duce the affected person to contact a physician. Correct interpretation of such symptoms and choice of appro- priate psychophysical examination methods will usually provide the examiner with specific information on topography and eventual progression, if baseline results are available [3,6].These data are essential prerequisites for effective neuroimaging, as well as for an adequate follow-up. Fig. 1 Functional anatomy of the human visual pathways Functional anatomy of the human visual pathways About 7 million cones and approximately 120 million The different sections of the visual pathways differ rods are distributed on the human retinal surface (area markedly with respect to the number,density and extent ~ 12 cm2). Each retinal element is directly linked to a of “intermixture” of neuronal elements, which will specific location within the visual field. More than strongly influence local resolution power and diagnos- 10 million bipolar cells forward the visual information tic relevance (Fig. 1). onto only 1.2 million ganglion cells.These cells are wide- spread on the retinal surface, and converge to 300–500 fibre-bundles with a total surface area of less than Received: 18 January 2003 0.2 cm2. There is a maximum neuronal density in the re- Accepted: 30 January 2003 gion of the optic chiasm: the entire visual information is “packed” into this “visual bottleneck” of about 1 cm3! In Prof. -
Miotics in Closed-Angle Glaucoma
Brit. J. Ophthal. (I975) 59, 205 Br J Ophthalmol: first published as 10.1136/bjo.59.4.205 on 1 April 1975. Downloaded from Miotics in closed-angle glaucoma F. GANIAS AND R. MAPSTONE St. Paul's Eye Hospital, Liverpool The initial treatment of acute primary closed-angle Table i Dosage in Groups I, 2, and 3 glaucoma (CAG) is directed towards lowering intraocular pressure (IOP) to normal levels as Group Case no. Duration IOP Time rapidly as possible. To this end, aqueous inflow is (days) (mm. Hg) (hrs) reduced by a drug such as acetazolamide (Diamox), and aqueous outflow is increased via the trabecular I I 2 8 5 meshwork by opening the closed angle with miotics. 3 7 21 3 The use of miotics is of respectable lineage and hal- 5 '4 48 7 lowed by usage, but regimes vary from "intensive" 7 8 I4 5 9 I0 I8 6 (i.e. frequent) to "occasional" (i.e. infrequent) instilla- I I 2 12 6 tions. Finally, osmotic agents are used after a variable '3 5 20 6 interval of time if the IOP remains raised. Tlle pur- I5 '4 I8 6 pose of this paper is to investigate the value of '7 '4 i6 6 miotics in the initial treatment of CAG. I9 6 02 2 2 2 8 2I 5 Material and methods 4 20t 20 6 Twenty patients with acute primary closed-angle glau- 6 I i8 5 http://bjo.bmj.com/ coma were treated, alternately, in one of two ways 8 4 i8 5 detailed below: I0 6 I8 6 I2 I0 20 6 (I) Intravenous Diamox 500 mg.