DOCSLIB.ORG

Successful Treatment Ofanisometropic Amblyopia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Successful Treatment Ofanisometropic Amblyopia BritishJournalofOphthalmology 1993; 77: 321-322 321 Successful treatment ofanisometropic amblyopia and strabismus following intravitreal silicone oil Br J Ophthalmol: first published as 10.1136/bjo.77.5.321 on 1 May 1993. Downloaded from RR Goble, W A Franks, D Avery, A H Chignell Silicone oil is used in the treatment of complex assessment with Bagolini glasses and Worth's retinal detachments. Its refractive index (1-400- four light test. 1 405) is higher than that ofvitreous (1-336) and Six months postoperatively no manifest devia- can cause a refractive change to high hyper- tion was present and the TNO stereoacuity was metropia in the phakic emmetropic eye.' This 240 seconds of arc. At 1 year full binocular degree of anisometropia can lead to the develop- function had returned with a TNO stereoacuity ment of amblyopia in young children. of60 seconds ofarc and there was a prism fusion A 6-year-old boy developed a traumatic retinal range of 20 dioptres base in and 45 dioptres base detachment successfully treated by vitrectomy out. and intravitreal silicone oil. Postoperative aniso- More than 2 years after the injury the left metropic amblyopia and secondary esotropia visual acuity is 6/6, the lens is clear, and the developed. The amblyopia was successfully retina remains attached. There is no manifest treated with hypermetropic spectacles and occlu- squint and the patient retains full stereoscopic sion. This was followed by oil removal and vision. strabismus surgery. Full stereopsis eventually recovered. Comment Retinal detachments in children are uncommon Case report and are often traumatic in origin. If there is A 6-year-old boy was referred 1 month after associated anterior segment damage and/or blunt trauma to his left eye with an inferior retinal detachment involving the macula then the retinal detachment and a post-equatorial break visual prognosis may be poor. If the macula at 8 o'clock associated with preretinal mem- remains attached and there is no significant brane. The macula was uninvolved and there anterior segment injury then the visual results was no significant anterior segment damage. after surgery should be excellent. Since initial presentation, the left visual acuity Silicone oil is useful in the treatment of eyes had been 6/18 due to vitreous haemorrhage. with complex retinal detachments."4 The long The patient had passed a school eye test the term complications of silicone oil include previous year. A pars plana vitrectomy was glaucoma, cataract, silicone oil emulsification, http://bjo.bmj.com/ performed with peeling of the membrane and, in aphakic eyes, corneal opacification.5-7 surrounding the break. The retinal break was Provided the retina remains attached, silicone judged to be too posterior for scleral buckling oil removal may prevent such problems so internal tamponade with silicone oil was arising. '° used. Children up to 8 years of age may develop Ten days postoperatively, the unaided left amblyopia." The reduction in visual acuity to visual acuity was counting fingers, which 6/18 at presentation and for 1 month before on September 27, 2021 by guest. Protected copyright. improved to 6/60 with + 8 dioptre sphere (cyclo- detachment surgery was caused by the vitreous plegic refraction: 0-00/+050x90 right and haemorrhage from the original injury. However, +8 00/+0 50x 170 left). A left esotropia had also following intravitreal silicone oil injection, the developed, measuring 35 prism dioptres at both uncorrected visual acuity dropped to counting 1/3 m and 6 m with the prism reflection test. Eye fingers and even with the full refractive correc- movements were full with normal saccades. The tion the acuity was only 6/60. It was evident that retina was attached, the fovea appeared normal in the absence of any structural abnormality the on biomicroscopy, and there were no media patient had developed silicone oil induced aniso- opacities. A diagnosis ofamblyopia with second- metropic amblyopia. Department of ary esotropia was made. The amblyopia was The esotropia developed within the first 10 Ophthalmology treated for 1 hour each day with glasses and days after surgery and was secondary to the R R Goble occlusion of the right eye. a of W A Franks anisometropic amblyopia. Following period A H Chignell The left visual acuity improved to 6/18 with loss ofbinocularity, a well controlled phoria may 1 month of treatment, and by 3 months was 6/6. decompensate. This is a possible mechanism in Department of The left esotropia persisted. The silicone oil was this case. The 'blind spot syndrome', in which Orthoptics, St Thomas's Hospital, removed. Forced duction testing and explora- the diplopic image falls on the optic disc of the Lambeth Palace Road, tion of the horizontal recti were normal. A 5 mm deviating eye, may be responsible for the large London SEI 7EH medial rectus recession and a 7 mm lateral rectus angle (35 prism dioptres) ofsquint in this case as D Avery resection were performed. well as the initial absence of diplopia." In some Correspondence to: Mr R R Goble, Department of Two weeks after silicone oil removal, the left trauma cases, fibrosis of the extraocular muscles Ophthalmology, Kent and visual acuity was 6/6 unaided (+0 00/+050x can produce strabismus. In this case the rapidity Canterbury Hospital, Canterbury, Kent CT1 3NG. 170 left). A 10 prism dioptre esotropia at 1/3 m of onset, full movements, and normal muscle Accepted for publication and 6 m persisted. The patient experienced inspection all failed to support this aetiology. 26 January 1993 diplopia and this was confirmed on orthoptic Detachment surgery itself may produce 322 Goble, Franks, Avery, Chignell to this 1 Lean JS. Use of silicone oil as an additional technique in strabismus. The factors which predispose vitreoretinal surgery. In: Ryan SJ, ed. Retina. Glaser BM, include the placement of scleral explants, scieral Michels RG, eds. Surgical retina. St Louis: Mosby, 1989: rectus conjunc- 289-90. dissection beneath muscles, and 2 Cibis PA, Becker B, Okun E, Canaan S. The use of liquid tival scarring, none of which was a factor in this silicone in retinal detachment surgery. Arch Ophthalmol Br J Ophthalmol: first published as 10.1136/bjo.77.5.321 on 1 May 1993. Downloaded from case. 13 1%2; 68: 590-9. 3 Scott JD. The treatment of massive vitreous retraction. Trans Loss of stereopsis occurred during the time Ophthalmol Soc UK 1975; 95: 429-32. eye, as the 4 Lean JS, Leaver PK, Cooling RJ, McLeod D. Management of that silicone oil remained within the complex retinal detachments by vitrectomy and fluid/ high degree of anisometropia produced insuper- silicone oil exchange. Trans Ophthalmol Soc UK 1985; 102: After the oil was removed, a 203-5. able aniseikonia. 5 McCuen B, de Juan E, Landers MB, Machemer R. Silicone oil small esotropia persisted for a few weeks until in vitreoretinal surgery. 2: Results and complications. single vision and eventually full Retina 1985; 5: 198-205. binocular 6 Leaver PK, Garner A, Grey RHB, Hitchings RA. Effects of stereopsis recovered. Unfortunately this intraocular silicone. Trans Ophthalmol Soc UK 1987; 97: 633. recovery may not always occur following 7 Leaver PK, Grey RHB, Garner A. Silicone oil in the treatment transient visual impairment in children, even in of massive preretinal retraction. Late complications in 93 those known previously to have had normal eyes. BrJ Ophthalmol 1979; 63: 361-7. 8 Casswell AG, Gregor ZJ. Silicone oil removal: 1 The effects on binocular single vision.'4 the complications of silicone oil. BrJ Ophthalmol 1987; 71: This case illustrates the importance of testing 893-7. 9 Franks WA, Leaver PK. Removal of silicone oil - rewards and for silicone oil induced anisometropia in young penalties. Eye 1991; 5: 333-7. children. It demonstrates that occlusion com- 10 Gonvers M. Temporary silicone oil tamponade in the manage- ment of retinal detachment with proliferative vitreoretino- bined with the use of hypermetropic spectacles pathy. AmJ Ophthalmol 1985; 100: 239-45. can prevent and treat the associated amblyopia 11 Harwerth RS, Smith EL, Duncan GC, Crawford MLJ, von Noorden GK. Multiple sensitive periods in the development which may compromise the results of otherwise ofthe primate visual system. Science 1986; 232: 235-8. successful detachment surgery. Removal of 12 Swan KC. The blind spot syndrome. Arch Ophthalmol 1948; 40: 371-88. silicone oil should be undertaken as soon as 13 Munoz M, Rosenbaum AL. Long-term strabismus complica- possible to minimise the risk of developing this tions following retinal detachment surgery. J Pediatr Ophthalmol Strabismus 1987; 24: 309-14. as well as its other long term complications. 14 Pratt-Johnson JA, Tillson G. Intractable diplopia after vision restoration in unilateral cataract. Am J Ophthalmol 1989; 107:23-6. http://bjo.bmj.com/ on September 27, 2021 by guest. Protected copyright..
Load more

Recommended publications
  • Pediatric Anisometropia: Case Series and Review
    Pediatric Anisometropia: tacles, vision therapy, and occlusion. Case two Case Series and Review is anisometropia caused by organic vision loss from optic neuritis early in life. Case three is John D. Tassinari OD, FAAO, FCOVD an infant with hyperopic anisometropia and Diplomate Binocular Vision esotropia. The esotropia did not respond to Perception and Pediatric Optometry, spectacles and home based vision therapy. American Academy of Optometry Neonatal high bilateral hyperopia that Associate Professor Western converted to anisometropia because of early University of Health Sciences onset cosmetically invisible unilateral esotropia College of Optometry is speculated. Case four describes a boy Pomona, California diagnosed with hyperopic anisometropia at age 11 months coincident with a diagnosis of pseudoesotropia. His compliance with ARTICLE prescribed spectacles was spotty until age three years. An outstanding visual outcome ABSTRACT was achieved by age five years with spectacles Background only (no occlusion therapy). Case five concerns The etiology and natural course and history a boy who acquired hyperopic anisometropia of pediatric anisometropia are incompletely because one eye experienced increasing understood. This article reviews the literature hyperopia during his toddler years. His regarding pediatric anisometropia with much response to treatment, spectacles and part of the review integrated into a case series. time occlusion with home vision therapy, was The review and case reports are intended to outstanding. Case six is an infant diagnosed elevate clinical understanding of pediatric with 2.50 diopters of hyperopic anisometropia anisometropia including and especially at age six months. Monocular home based treatment outcomes. vison developmental activities, not glasses, were prescribed. Her anisometropia vanished Case Reports three months later.
    [Show full text]
  • WSPOS Worldwide Webinar 16: Amblyopia - How and When
    Answers to Audience Questions - WSPOS Worldwide Webinar 16: Amblyopia - How and When WWW 16 Panellists Anna Horwood Celeste Mansilla David Granet Krista Kelly Lionel Kowal Susan Cotter Yair Morad Anna Horwood (AH), Celeste Mansilla (CM), Krista Kelly (KK), Lionel Kowal (LK), Susan Cotter (SC), Yair Morad (YM) 1. How do you maintain attained iso visual acuity after successful amblyopia treatment? AH: Intermittent monitoring. If they have regressed previously, I might carry on very intermittent occlusion (an hour or two a week) until I was sure it was stable. CM: With gradual and controlled reduction of the treatment, for example: if the patient had 1 hour of patch per day, I leave it with 1 hour 3 times a week during a month. I do a check and if the visual acuity was maintained, I lower patches to 2 times a week. I keep checking and going down like this until I suspend the treatment. If at any time I detect worsening visual acuity, I return to the previous treatment. SC: Best way is attainment of normal binocular vision. I do not worry about ansiometropic amblyopes who have random dot stereopsis post-treatment. If have constant unilateral strabismus, I can do some limited part-time patching, decreasing patching dosage over time given no regression of VA. YM: repeat examination every 6 months. If I see regression, I will prescribe patching for 30 min a day. 2. How do you plan for very dense amblyopes? AH: I very rarely see them because, with screening, they are picked up early and usually do well.
    [Show full text]
  • Strabismus, Amblyopia & Leukocoria
    Strabismus, Amblyopia & Leukocoria [ Color index: Important | Notes: F1, F2 | Extra ] EDITING FILE ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Objectives: ➢ Not given. Done by: Jwaher Alharbi, Farrah Mendoza. ​ ​ Revised by: Rawan Aldhuwayhi ​ Resources: Slides + Notes + 434 team. ​ ​ NOTE: F1& F2 doctors are different, the doctor who gave F2 said she is in the exam committee so focus on her notes Amblyopia ● Definition Decrease in visual acuity of one eye without the presence of an organic cause that explains that decrease ​ ​ in visual acuity. He never complaints of anything and his family never noticed any abnormalities ​ ● Incidence The most common cause of visual loss under 20 years of life (2-4% of the general population) ● How? Cortical ignorance of one eye. This will end up having a lazy eye ​ ● binocular vision It is achieved by the use of the two eyes together so that separate and slightly dissimilar images arising in each eye are appreciated as a single image by the process of fusion. It’s importance 1. Stereopsis 2. Larger field If there is no coordination between the two eyes the person will have double vision and confusion so as a compensatory mechanism for double vision the brain will cause suppression. The visual pathway is a plastic system that continues to develop during childhood until around 6-9 years of age. During this time, the wiring between the retina and visual cortex is still developing. Any visual problem during this critical period, such as a refractive error or strabismus can mess up this developmental wiring, resulting in permanent visual loss that can't be fixed by any corrective means when they are older Why fusion may fail ? 1.
    [Show full text]
  • Refractive Changes After Scleral Buckling Surgery
    Refractive changes after scleral buckling surgery Alterações refracionais após retinopexia com explante escleral João Jorge Nassaralla Junior1 ABSTRACT Belquiz Rodriguez do Amaral Nassaralla2 Purpose: A prospective study was conducted to compare the refractive changes after three different types of scleral buckling surgery. Methods: A total of 100 eyes of 100 patients were divided into three groups according to the type of performed buckling procedure: Group 1, encircling scleral buckling (42 patients); Group 2, encircling with vitrectomy (30 patients); Group 3, encircling with additional segmental buckling (28 patients). Refractive examinations were performed before and at 1, 3 and 6 months after surgery. Results: Changes in spherical equivalent and axial length were significant in all 3 groups. The amount of induced astigmatism was more significant in Group 3. No statistically significant difference was found in the amount of surgically induced changes between Groups 1 and 2, at any postoperative period. Conclusions: All three types of scleral buckling surgery were found to produce refractive changes. A correlation exists between additional segments and extent of refractive changes. Keywords: Retinal detachment/surgery; Scleral buckling/adverse effects; Refraction/ ocular; Biometry INTRODUCTION During the past several years, our Retina Service and others(1) have continued to use primarily solid implants with encircling bands. Only occa- sionally episcleral silicone rubber sponges are utilized. Changes in refrac- tion are frequent after retinal detachment surgery. The surgical technique used appears to influence these changes. Hyperopia(2) and hyperopic astig- matism may occur presumably by shortening the anteroposterior axis of the globe after scleral resections(1). Scleral buckling procedures employing an encircling band generally are expected to produce an increase in myopia and myopic astigmatism(1,3).
    [Show full text]
  • Vision Services Professional Payment Policy Applies to the Following Carepartners of Connecticut Products
    Vision Services Professional Payment Policy Applies to the following CarePartners of Connecticut products: ☒ CareAdvantage Premier ☒ CareAdvantage Prime ☒ CareAdvantage Preferred ☒ CarePartners Access The following payment policy applies to ophthalmologists who render professional vision services in an outpatient or office setting. In addition to the specific information contained in this policy, providers must adhere to the policy information outlined in the Professional Services and Facilities Payment Policy. Note: Audit and disclaimer information is located at the end of this document. POLICY CarePartners of Connecticut covers medically necessary vision services, in accordance with the member’s benefits. GENERAL BENEFIT INFORMATION Services and subsequent payment are pursuant to the member’s benefit plan document. Member eligibility and benefit specifics should be verified prior to initiating services by logging on to the secure Provider portal or by contacting CarePartners of Connecticut Provider Services at 888.341.1508. Services, including periodic follow-up eye exams, are considered “nonpreventive/nonroutine” for members with an eye disease such as glaucoma or a condition such as diabetes. Routine Eye Examinations and Optometry Medical Services CarePartners of Connecticut has arranged for administration of the vision benefit through EyeMed Vision Care. Ophthalmologists Ophthalmologists must be contracted with EyeMed Vision Care in order to provide routine eye services or dispense eyewear to CarePartners of Connecticut members. Ophthalmologists may provide nonroutine, medical eye services to members according to their CarePartners of Connecticut agreement. REFERRAL/PRIOR AUTHORIZATION/NOTIFICATION REQUIREMENTS Certain procedures, items and/or services may require referral and/or prior authorization. While you may not be the provider responsible for obtaining prior authorization, as a condition of payment you must confirm that prior authorization has been obtained.
    [Show full text]
  • Amblyopia HANDOUT ACES
    AMBLYOPIA CORNEA PUPIL CATARACT IRIS LENS RETINA MACULA OPTIC NERVE The eye on the right is at risk for all three types of AMBLYOPIA. Rays of light enter the normal eye on the left, are bent by the cornea and the lens and are focused one the most precise part of the retina called the macula. Light entering the right eye is disrupted by a congenital cataract (deprivational amblyopia). Since the right eye is shorter than the left, light doesn't focus on the retina due to unequal far-sightedness(refractive amblyopia). Since the left eye is crossed (esotropia-type strabismus), incoming light fails to align on the macula (strabismic amblyopia). ye doctors and orthoptists want each child to grow frequently suppresses or "turns off" the brain image from up with the healthiest visual system possible. the non-dominant eye. Strabismic amblyopia can be E This goal requires the close cooperation of treated by combinations of drops, glasses, patching parents, pediatricians, primary doctors, optometrists, and/or eye muscle surgery. school nurses and health aids and the professionals who DETECTION: Within the first days after birth, deal with visually impaired babies. part of each baby's first physical exam is the "red reflex" an abnormality of which could indicate cataract or tumor. At birth, a normal infant has relatively poor vision in the range A part of routine pre-school pediatric check-ups is of 20/2000! Under normal conditions, the visual system improves so that observations of red reflex by photoscreen and Brückner 20/20 vision might be attained by school age and retained after age 10 years.
    [Show full text]
  • Association of British Dispensing Opticians Heads You Win, Tails
    Agenda Heads You Win, Tails You Lose • The correction of ametropia • Magnification, retinal image size, visual Association of British The Optical Advantages and acuity Disadvantages of Spectacle Dispensing Opticians • Field of view Lenses and Contact lenses • Accommodation and convergence 2014 Conference Andrew Keirl • Binocular vision and anisometropia Kenilworth Optometrist and Dispensing Optician • Presbyopia. 1 2 3 Spectacle lenses Contact lenses Introduction • Refractive errors that can be corrected • Refractive errors that can be corrected using • Patients often change from a spectacle to a using spectacle lenses: contact lenses: contact lens correction and vice versa – myopia – myopia • Both modes of correction are usually effective – hypermetropia in producing in-focus retinal images – hypermetropia • apparent size of the eyes and surround in both cases • There are of course some differences – astigmatism – astigmatism between modes, most of which are • not so good with irregular corneas • better for irregular corneas associated with the position of the correction. – presbyopia – presbyopia • Some binocular vision problems are • Binocular vision problems are difficult to manage using contact lenses. easily managed using spectacle lenses. 4 5 6 The correction of ametropia using Effectivity contact lenses • A distance correction will form an image • Hydrogel contact lenses at the far point of the eye – when a hydrogel contact lens is fitted to an eye, The Correction of Ametropia the lens “drapes” to fit the cornea • Due to the vertex distance this far point – this implies that the tear lens formed between the will lie at slightly different distances from contact lens and the cornea should have zero the two types of correcting lens power and the ametropia is corrected by the BVP of the contact lens – the powers of the spectacle lens and the – not always the case but usually assumed in contact lens required to correct a particular practice eye will therefore be different.
    [Show full text]
  • 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
    [Show full text]
  • Retinal Detachment with Subretinal and Vitreous Hemorrhages Causing Secondary Angle Closure Glaucoma Diagnosed with Ultrasound
    Henry Ford Health System Henry Ford Health System Scholarly Commons Emergency Medicine Articles Emergency Medicine 5-22-2020 Retinal detachment with subretinal and vitreous hemorrhages causing secondary angle closure glaucoma diagnosed with ultrasound Michael B. Holbrook Daniel Kaitis Lily Van Laere Jeffrey Van Laere Christopher R. Clark Follow this and additional works at: https://scholarlycommons.henryford.com/ emergencymedicine_articles YAJEM-159017; No of Pages 2 American Journal of Emergency Medicine xxx (xxxx) xxx Contents lists available at ScienceDirect American Journal of Emergency Medicine journal homepage: www.elsevier.com/locate/ajem Retinal detachment with subretinal and vitreous hemorrhages causing secondary angle closure glaucoma diagnosed with ultrasound Michael B. Holbrook, MD, MBA a,⁎, Daniel Kaitis, MD b, Lily Van Laere, MD b, Jeffrey Van Laere, MD, MPH a, Chris Clark, MD a a Henry Ford Hospital, Department of Emergency Medicine, Detroit, MI, United States of America b Henry Ford Hospital, Department of Ophthalmology, Detroit, MI, United States of America A 90-year-old female with a past medical history of trigeminal neu- choroid/retina consistent with a retinal detachment. Her pain was con- ralgia and age-related macular degeneration (AMD) presented with a trolled with oral hydrocodone/acetaminophen. Ultimately her vision four-day history of a left-sided headache, nausea, and vomiting. Regard- was deemed unsalvageable given her age, length of symptoms, and ing her left eye, she reported intermittent flashes of light over the past lack of light perception. At time of discharge, her left eye's IOP was month and complete vision loss for four days. She denied a history of di- 49 mmHg.
    [Show full text]
  • Retinopathy of Prematurity: an Update Parveen Sen, Chetan Rao and Nishat Bansal
    Review article Retinopathy of Prematurity: An Update Parveen Sen, Chetan Rao and Nishat Bansal Sri Bhagwan Mahavir Introduction 1 ml of 10% phenylephrine (Drosyn) mixed in 3 ml Vitreoretinal Services, Retinopathy of prematurity (ROP) was originally of 1% tropicamide (after discarding 2 ml from 5 ml Sankara Nethralaya designated as retrolental fibroplasias by Terry in bottle) for pupillary dilatation. These combination 1952 who related it with premature birth.1 Term drops are used every 15 minutes for 3 times. 2 Correspondence to: ROP was coined by Heath in 1951. Punctum occlusion is mandatory after instilling the Parveen Sen, It is a disorder of development of retinal blood drops to reduce the systemic side effects of medica- Senior Consultant, vessels in premature babies. Normal retinal vascu- tion. Excess eye drops should also be wiped off to Sri Bhagwan Mahavir larization happens centrifugally from optic disc to prevent absorption through cheek skin. If the pupil Vitreoretinal Services, ora. Vascularization up to nasal ora is completed does not dilate in spite of proper use of medication, Sankara Nethralaya. by 8 months (36 weeks) and temporal ora by 10 presence of plus disease should be suspected. E-mail: [email protected] months (39–41 weeks).3 Repeated installation of topical drops should be The incidence of ROP is increasing in India avoided to prevent systemic problems. Sterile because of improved neonatal survival rate. Out of Alfonso speculum is used to retract the lids and wire 26 million annual live births in India, approxi- vectis for gentle depression. mately 2 million are <2000 g in weight and are at High-quality retinal images obtained using risk of developing ROP.3 In India the incidence of commercially available wide-angle fundus camera ROP is between 38 and 51.9% in low-birth-weight like the Retcam followed by Telescreening by a infants.3,4 trained ophthalmologist can also be done.
    [Show full text]
  • Human Amblyopia
    Human Amblyopia • “Lazy Eye” • Relatively common developmental visual disorder (~2%) • Reduced visual acuity in an otherwise healthy and properly corrected eye • Associated with interruption of normal early visual experience • Most common cause of vision loss in children • Well characterized behaviorally, not neurologically • Treated by patching in children Visual Deficits in Amblyopia • Reduced monoc. visual acuity - defining feature – Usually 20/30 - 20/60 • Impaired contrast sensitivity – Prominent at high spatial frequencies Contrast Sensitivity Sensitivity Contrast – Central visual field is generally most affected Spatial Frequency • Moderate deficits in object segmentation/recognition and spatial localization • Severe deficits in binocular interactions Subtypes of Amblyopia • Anisometropic – Unequal refractive error between the two eyes • Strabismic – Deviated eye that may or may not have unbalanced refraction • Deprivation – Congenital cataract; corneal opacity; eyelid masses Mechanisms of Amblyopia 1. Form deprivation . Sharp image is not formed at the retina 2. Abnormal binocular vision . Binocularity is often changed or lost in amblyopia Models of Amblyopia • Competition hypothesis originated with experiments in kittens in the 1960s by Hubel and Wiesel • Monocular deprivation of retinal input during ‘critical’ developmental periods leads to striking abnormalities in the physiology of visual cortical neurons • Binocular deprivation actually leads to less severe abnormalities • Amblyopia may be a form of activity-dependent deprivation,
    [Show full text]
  • Complex Retinal Detachment
    RETINA HEALTH SERIES | Facts from the ASRS The Foundation American Society of Retina Specialists Committed to improving the quality of life of all people with retinal disease. Complex Retinal Detachment: SYMPTOMS Proliferative Vitreoretinopathy and Giant Retinal Tears Proliferative vitreoretinopathy (PVR) is a condition in which Many patients with PVR report retinal scar tissue, or “membranes” form; this may occur symptoms of retinal traction with a retinal detachment. A key risk factor for developing (pulling), such as floaters or flashes of light. Accumulation of PVR is a giant retinal tear—a large tear that involves at least fluid underneath the retina results 25% of the retina. When PVR or a giant retinal tear is in a loss of peripheral (side) vision. present, a retinal detachment is classified as “complex.” When the detachment involves the center of the retina, called Causes: Complex retinal detachments due to PVR are associated with retinal the macula, central vision loss will scar tissue or membranes; these ultimately contract, pull, and stretch the occur. Patients with chronic retinal retina, causing retinal tears or stretch holes. When the detached retina detachment may also develop contracts, so-called “star folds” often develop (Figure 1). problems such as elevated pressure The reason these membranes in the eye and inflammation. form is uncertain, but it is thought Some patients experience no to be due to cells growing on the symptoms, particularly: retinal surface. Passage of liquefied • Younger patients vitreous gel through a retinal tear • Cases where the macula is not or hole results in an accumulation involved of fluid under the retina (subretinal • Patients whose detachment has fluid) and progression of the progressed slowly retinal detachment.
    [Show full text]