Amblyopia

A peculiar occasional observation prompted our attention some years ago on the relationship between age-related macular degeneration (AMD) and amblyopia. A 75-year old gentleman, family friend of one of us (ECC) for decades, developed an hemorragic type of AMD in his sound eye. The other eye had a severe strabismic amblyopia, with excentric fixation and a visual acuity not better than 6/30. Initial fluorangiographic retinal changes were present in this eye as well. Over an eight year period no functional deterioration took place in the amblyopic eye, with only light perception present in the sound eye. Based on this clinical observation, we undertook a prospective study for evaluating the time course of a possible symmetrization of AMD in patients with strabismic amblyopia in which AMD started in the non-amblyopic eye. Ten patients initially presenting with clinically relevant AMD in one eye have been followed over a six year period. Five had esotropia with deep amblyopia of the deviated eye and five had normal binocular vision. The amblyopic patients were selected on the basis of the presence of an AMD in the sound eye. Visual acuity measurements and retinal fluorescein angiography (RFA) were repeated annually, in order to detect the time course of involvement of the second eye. Visual acuity of the eye with AMD in the patients with strabismic amblyopia of the other eye deteriorated rapidly to levels lower than that of the amblyopic eye (between 2 and 8 months from the initial observation). In the amblyopic eye, there was no change in the visual acuity over the six year period. In the strabismic patients the macular lesions of the eyes with AMD deteriorated from an hemorragic to a cicatricial stage in all five patients after 2 to 12 months. The RFA of the amblyopic eye showed initial changes, i.e., 'typical' or 'exudat-ive' drusen, after 6 to 48 months from the beginning of the study. Visual acuity testing in both eyes of the five patients without strabismus showed a progressive although slow deterioration in both the originally affected eye and the second eye. An initial deterioration of visual acuity in the second eye could be observed after 12 to 38 months from the beginning of the study. Visual acuity in the two eyes tended to be equal at the end of the observation period of six years. The earliest signs of the disease in the originally non-affected eye were revealed by RFA after 8 to 24 months from the beginning of the study.

ABSTRACT Amblyopia is a developmental ocular disease of childhood-onset which may lead to persistent sequelae into adulthood. Early detection and management of amblyopia usually result in an improved visual outcome. The purpose of this study was to determine the prevalence and pattern of amblyopia in a rural hospital in Ghana. Clinical records of patients seen (from January 2014 to December 2018) at Westphalian Medical Center, Oyoko, Ashanti Region, Ghana, were reviewed retrospectively. Unilateral amblyopia was defined as a two-line interocular difference or more in visual acuity. Bilateral amblyopia was defined as best-corrected visual acuity (BCVA) of Snellen 6/12 or worse in both eyes, with evidence of bilateral ametropia or obstruction of the visual pathway. Following a review of 12,602 patient records, 258 cases of amblyopia were identified. The mean (±SD) presenting age of amblyopic patients was 24.3 ± 16.1 years, with a male-to-female ratio of 1:1.1. The period prevalence of amblyopia was 2.04%. The period prevalence of unilateral and bilateral amblyopia was 1.38% and 0.66%, respectively. The most prevalent form of amblyopia was refractive with a cumulative prevalence of 1.42%. Strabismic and stimulus deprivation amblyopia accounted for 0.36% and 0.21% of all amblyopic cases, respectively. A major cause of amblyopia in this population was refractive error, hence the use of spectacle correction for its initial management. Repeated assessment after an appropriate period of refractive adaptation would elucidate the proportion of amblyopias needing additional treatment modalities. Vision screening for early detection of amblyopia in childhood with accessible and effective management of amblyopia (including refractive correction and occlusion treatment) is necessary to reduce the impact of amblyopia in Ghana.

Non-strabismic, non-amblyopic intermittent central suppression (ICS) has been the crux of the challenge I have in accepting the conventional wisdom of suppression development: " Diplopiaphobia. " Reconciling the on-again, off-again intermittent loss of visual sensation that is ICS with cortical inhibition (often defined as masking at the cortex 1) as the proposed visual sensation shutdown mechanism is just hard. That inhibition must not only be intermittent, but alternating from side to side (in 80% of ICS patients) uncontrolled by some sort of volitional switch in fixation as occurs sometimes in alternating strabismus. Those shortcomings led me to explore how the vision science on visibility might apply to this intermittent type of suppression 2. My starting point was that the visual neurology is, well, the visual neurology. That is, whether strabismus is present or not, the neurology responsible for the suppression is in its basic construction-or perhaps in its beginning construction-the same, assuming no gross genetic or trauma-caused defects. The conventional wisdom, then, would hold that strabismus or anisometropia, through diplopiaphobia shuts down recognition of the visual signal for one side at the cortex and that defines suppression. But, if we redefine loss of the visual signal as vision science might, that is, as a loss of visibility (Troxlerʼs Perceptual Fading, possibly ICS 2), that loss of visibility is positioned as a more afferent-maybe more primary-visual sensory defect rather than being entirely secondary to misalignment or anisometropia. If accurate, an early interruption of visibility (visual sensation) changes the time course of sensory anomalies from current thought. With diplopiaphobia, although unstated, there's always a sense that " the organism " actively decides over time that diplopia doesn't work well. The diplopia comes first. If instead the sensory loss becomes more primary, the time-frame to defect may contract. And, in development of neurology and potential defects in development, time is of the essence. Exploring the consequences of loss of visibility to our view of the development of binocularity defects means putting that loss of visibility into the moving framework of time-inserting loss of visibility into the development of the visual neurology through time. But, moving the sensory defect from the cortex to the more afferent location of loss of visibility at or near the LGN also means any loss of visibility now affects development further upstream neurologically. Loss of visibility at the LGN, if developmentally early enough, has consequences for development at the cortex, versus the cortex interfering with its own development through masking. Science fiction has used intervention in the fourth dimension (time) as a vehicle for stories for decades. But, here we have real-life consequences through time from an early disturbance in information transfer. Assuming loss of visibility (that is, Troxlerʼs fading) may be responsible for the loss of sensation of intermittent central suppression led to the first suggested visual-behavioral consequence that I termed " visual dyslexia. " In this view, loss of visibility contributes to such classic behavioral descriptions of " dyslexia " as reading letters and words " backwards. " Loss of visibility not only creates fixation instability, but also surprisingly strong filling-in of the area that has lost visibility. 3 " Backwards " could easily be a short word seen correctly with one eye paired with a filled-in area from the fellow eye further confused (and variably confused?) by fixation instability. That the filling-in is strong enough to create rivalry with the " normally-seeing " eyeʼs image adds to the sense of loss-of-visibility variability in the central perception. This combination of a normal image conflicting with fixation-unstable filling-in could turn that short word into a variable visual mush-but a mush that has some " normal " characteristics from the non-suppressed eyeʼs image. Perhaps " seeing backwards " should be replaced with " confused image. " Importantly, this would move some of the visual part of " dyslexia "

Emerging technologies are now giving us unprecedented access to manipulate brain circuits, shedding new light on treatments for amblyopia. This research is identifying key circuit elements that control brain plasticity and highlight potential therapeutic targets to promote rewiring in the visual system during and beyond early life. Here, we explore how such recent advancements may guide future pharmacological, genetic, and behavioral approaches to treat amblyopia. We will discuss how animal research, which allows us to probe and tap into the underlying circuit and synaptic mechanisms, should best be used to guide therapeutic strategies. Uncovering cellular and molecular pathways that can be safely targeted to promote recovery may pave the way for effective new amblyopia treatments across the lifespan.

The validity and repeatability of visual acuity measures are particularly important in the detection and monitoring of childhood visual anomalies such as amblyopia. The repeatability and sensitivity of a new computerised visual acuity test, ÔStaircased ProcedureÕ is compared with the now gold standard visual acuity test, the early treatment of diabetic retinopathy study (ETDRS). Twenty-seven visually normal children (mean age: 6.7 ± 1.1 years) and 27 children with amblyopia (mean age: 6.1 ± 0.7 years) were tested with the ETDRS and Staircased Procedure. A retest was administered 4-5 weeks later and 30 min later for the visually normal and the amblyopic children, respectively. The staircased procedure produced significantly better visual acuity than the ETDRS for visually normal and amblyopic children. Repeatability was similar for both tests (ETDRS: 0.11 log units; staircased procedure: 0.13 log units). In conclusion, the Staircased Procedure was an acceptable test with high repeatability and validity.

Although historically, treatment of amblyopia has been recommended prior to closure of a critical window in visual development, the existence and duration of that critical window is currently unclear. Moreover, there is clear evidence, both from animal and human studies of deprivation amblyopia, that there are different critical windows for different visual functions and that monocular and binocular deprivation have different neural and behavioral consequences. In view of the spectrum of critical windows for different visual functions and for different types of amblyopia, combined with individual variability in these windows, treatment of amblyopia has been increasingly offered to older children and adults. Nevertheless, treatment beyond the age of 7 years tends to be, on average, less effective than in younger children, and the high degree of variability in treatment response suggests that age is only one of many factors determining treatment response. Newly emerging treatment moda...

Ophthalmologic symptoms are often not sufficiently accounted for by organic pathology. The complaints of these patients have been labeled hysterical, psychogenic, nonorganic, or functional. The psychiatric nosology in this area may be the most confusing in the whole field of clinical medicine. The Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) offers a classification designed to reduce non-empirical concepts and ideology to a minimum. On this background, we discuss the hysterical symptoms encountered in clinical ophthalmology with special emphasis on psychogenic amblyopia and blepharospasm. Motor symptoms are commonly not of psychogenic origin. It is suggested that ophthalmologists are most likely to treat patients with psychogenic symptoms, using suggestion, patience, and reassurance. Few patients require psychiatric consultation and a specific psychiatric therapy. The association of hysteria with organic brain disease and the issue of symptom lateralization are briefly discussed. Eventually, we reject the psychoanalytic approach and suggest that the concept of abnormal illness behavior and the neurobiological models involving corticofugal inhibition, primitive reflex mechanisms, and an attention disturbance, serve best to understand the nature of the phenomenon hysteria.

We describe a psychophysical method for assessing binocular integration using dichopticallypresented uniform fields. By temporally modulating uniform field luminances at different frequencies between the eyes, a rhythmic bear is produced-a visual percept characterized by undulations in luminance at a frequency equal to the arithmetic difference between the two monocular stimulus frequencies. Using a signal detection paradigm, we studied the beat as a function of modulation depth in normal and binocularly deficient subjects. Normal subjects easily detected the beat, even at low modulation depths, while stereoblind subjects (with stereoacuity worse than 2OOOsec arc) failed to detect beats at any modulation depth or with any combination of stimulus frequencies tested. The beat provides evidence for the confluence of monocular signals into binocular integrating mechanisms. Our results therefore suggest that the status of functioning binocular mechanisms is related to the detectability of the beat. This uniform-field stimulus does not require accurate accommodation, fixation, vergence or high spatial resolution, thus making this technique particularly attractive for the study of binocular interaction in developing infants and in binocularly deficient adults. Binocular interaction Beats Psychophysics Amblyopia Nonlinear mechanisms Uniform fields Temporal

The major types of ametropia and visual problems for Hong Kong Chinese and Caucasian children are different. Consequently, the referral criteria developed for Caucasian children may not be applicable to Hong Kong children. Results of our study suggested that the referral criteria for Hong Kong children should be set as hyperopia of ≥+ 2.0 D, myopia of ≥ 1.0 D, anisometropis of ≥ 1.0 D and anisometropia of ≥ 1.25 D. Sensitivity using only these criteria for abnormal refraction in identifying children with amblyopia. Esotropia, exotropia and subnormal vision (< 6/12) was respectively 100%, 84.6%, 45.2% and 95.7%. The overall sensitivity for the identification of visual problems was 86.1 % and the overall specificity was 76%. If a cover test or a Hirschberg test was introduced into the screening battery so that all the strabismic cases were identified, the overall sensitivity would increase to 98.6%.

Amblyopia is one of the most common causes of visual impairment in adults and children, and visual loss may be permanent if not treated in time. Though many studies have been done on occlusion therapy which is the mainstay in the treatment of unilateral amblyopia, discrepancies exist in literature about quantification of treatment and follow up measures. The present study was undertaken to evaluate the factors responsible for the successful outcome of treatment and the optimum time required for the same in children with unilateral amblyopia. Baseline characteristics of 63 verbal patients with unilateral amblyopia (strabismic, anisometropic, mixed) referred to the Strabismus and Amblyopia Clinic at the Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi between September 2001 to December 2002 who improved to the desired level of visual acuity after treatment for amblyopia in the mentioned time period, were analyzed to assess for factors that directly or indirectly influenced...

PURPOSE. Development or restoration of binocular vision is one of the key goals of strabismus management; however, the functional impact of stereoacuity has largely been neglected. METHODS. Subjects aged 10 to 30 years with normal, reduced, or nil stereoacuity performed three tasks: Purdue pegboard (measured how many pegs placed in 30 seconds), bead threading (with two sizes of bead, to increase the difficulty; measured time taken to thread a number of beads), and water pouring (measured both accuracy and time). All tests were undertaken both with and without occlusion of one eye. RESULTS. One hundred forty-three subjects were recruited, 32.9% (n ϭ 47) with a manifest deviation. Performances on the pegboard and bead tasks were significantly worse in the nil stereoacuity group when compared with that of the normal stereoacuity group. On the large and small bead tasks, those with reduced stereoacuity were better than those with nil stereoacuity (when the Preschool Randot Stereoacuity Test [Stereo Optical Co, Inc., Chicago, IL] results were used to determine stereoacuity levels). Comparison of the short-term monocular conditions (those with normal stereoacuity but occluded) with nil stereoacuity showed that, on all measures, the performance was best in the nil stereoacuity group and was statistically significant for the large and small beads task, irrespective of which test result was used to define the stereoacuity levels. CONCLUSIONS. Performance on motor skills tasks was related to stereoacuity, with subjects with normal stereoacuity performing best on all tests. This quantifiable degradation in performance on some motor skill tasks supports the need to implement management strategies to maximize development of high-grade stereoacuity. (Invest Ophthalmol Vis Sci.

Purpose Anisometropia of more than one dioptre during the sensitive visual period may cause amblyopia. Its management requires refractive correction, and occlusion. Compliance with treatment is critical if visual improvement is to obtained. High anisometropia, poor initial acuity and mixed strabismic/anisometropia amblyopia are predictive factors for a poor outcome. We evaluated contact lens use in the management of high anisometropic amblyopia. Methods Retrospective analysis of anisometropic amblyopia managed in a paediatric contact lens clinic (July 1996-July 2000), after standard amblyopia therapy of spectacles and occlusion therapy had been tried. Presenting age, acuity and refraction, duration of lens wear and occlusion, and final visual outcomes were noted. Results Seven children (four male, three female) presented at age 3.5-6 years (mean 4.5). Six had myopic anisometropia 6.0-18.4 dioptres (mean 10.4 dioptres) and one 6.75 dioptres hypermetropic anisometropia. The initial corrected acuities of the amblyopic eyes were 6/18 to 1/60. Five patients used contact lenses with a range from 5 months to 4 years. Final acuities were 6/12-1/60. Two myopes with 6 dioptres anisometropia improved three to four Snellen lines, one with 8.8 dioptres improved one line. Three with Ͼ10 dioptres anisometropia did not improve. The hypermetropic patient improved part of one Snellen line. Conclusions High anisometropic amblyopia is challenging to treat. In our study contact lenses improved visual acuity in myopic anisometropia of up to 9 dioptres.

Amblyopia is a developmental ocular disease of childhood-onset which may lead to persistent sequelae into adulthood. Early detection and management of amblyopia usually result in an improved visual outcome. The purpose of this study was to determine the prevalence and pattern of amblyopia in a rural hospital in Ghana. Clinical records of patients seen (from January 2014 to December 2018) at Westphalian Medical Center, Oyoko, Ashanti Region, Ghana, were reviewed retrospectively. Unilateral amblyopia was defined as a two-line interocular difference or more in visual acuity. Bilateral amblyopia was defined as best-corrected visual acuity (BCVA) of Snellen 6/12 or worse in both eyes, with evidence of bilateral ametropia or obstruction of the visual pathway. Following a review of 12,602 patient records, 258 cases of amblyopia were identified. The mean (±SD) presenting age of amblyopic patients was 24.3 ± 16.1 years, with a male-to-female ratio of 1:1.1. The period prevalence of amblyopia...

Objective: To develop a questionnaire to assess the acceptability of amblyopia treatment and its effect on the child and family. Methods: A 20-item parental survey was developed and pilot tested on 64 subjects, aged 3 to 6 years, participating in the Amblyopia Treatment Study, a randomized trial comparing patching and atropine as treatments for moderate amblyopia. The survey was administered after 4 weeks of treatment. A descriptive item analysis and an internal consistency reliability analysis were performed. Results: Nineteen of the 20 items demonstrated adequate variability as evidenced by the frequency distributions for item responses. Only 4 (<1%) of 1280 possible item responses were missing, one each by 4 different respondents. Factor analysis identified 3 treatment-related factors-"adverse effects," "compliance," and "social stigma"-among 11 of the 20 items. The internal-consistency reliability α for the 5-item adverse effects subscale was 0.82, the 4-item compliance subscale α was 0.81, and the 2-item social stigma subscale α was 0.84. Conclusions: The Amblyopia Treatment Index appears to be a useful instrument for assessing the impact of amblyopia treatment in 3-to 6-year-old children. (J AAPOS 2001;5:250-4)

Purpose: To compare the Kay Picture Test and the logMAR Crowded Test. Methods: Monocular visual acuity measurement was attempted on 103 paediatric subjects (aged between 2.5 and 16 years) attending eye clinics, using each of the visual acuity tests. Results: The results obtained with the two tests were found to be comparable as confirmed with the Intra-class Correlation Coefficient, which revealed good agreement between the two tests. There was significant correlation between the visual acuity results measured and high conformity in the results from the weaker eye. There was a statistical difference in acuity scores between the tests; the Kay Picture Test gave a lower logMAR score with a mean difference of 0.08 logMAR. This 0.08 difference represents an actual difference of less than one line of acuity measure which can be considered to be clinically insignificant. There was a significant difference in the ability to perform each of the tests under binocular conditions, with more of the 50 children, aged 5 and under, able to perform the Kay Picture Test than the logMAR Crowded Test. Conclusions: The results obtained with the two tests are comparable. Both tests can be considered to be appropriate for amblyopia detection and the use of picture-based logMAR tests should be considered for younger children.

Aim: To describe the visual response to spectacle correction (''refractive adaptation'') for children with unilateral amblyopia as a function of age, type of amblyopia, and category of refractive error. Method: Measurement of corrected amblyopic and fellow eye logMAR visual acuity in newly diagnosed children. Measurements repeated at 6 weekly intervals for a total 18 weeks. Results: Data were collected from 65 children of mean (SD) age 5.1 (1.4) years with previously untreated amblyopia and significant refractive error. Amblyopia was associated with anisometropia in 18 (5.5 (1.4) years), strabismus in 16 (4.2 (0.98) years), and mixed in 31 (5.2 (1.5) years) of the study participants. Mean (SD) corrected visual acuity of amblyopic eyes improved significantly (p,0.001) from 0.67 (0.38) to 0.43 (0.37) logMAR: a mean improvement of 0.24 (0.18), range 0.0-0.6 log units. Change in logMAR visual acuity did not significantly differ as a function of amblyopia type (p = 0.29) (anisometropia 0.22 (0.13); mixed 0.18 (0.14); strabismic 0.30 (0.24)) or for age (p = 0.38) (''under 4 years'' 0.23 (0.18); ''4-6 years'' 0.24 (0.20); ''over 6 years'' 0.16 (0.23)). Conclusion: Refractive adaptation is a distinct component of amblyopia treatment. To appropriately evaluate mainstream therapies such as occlusion and penalisation, the beneficial effects of refractive adaptation need to be fully differentiated. A consequence for clinical practice is that children may start occlusion with improved visual acuity, possibly enhancing compliance, and in some cases unnecessary patching will be avoided. 1552 www.bjophthalmol.com

for Quality Eye Care without any external financial support. Authors and reviewers of the guidelines are volunteers and do not receive any financial compensation for their contributions to the documents. The guidelines are externally reviewed by experts and stakeholders before publication.

To investigate the level of agreement between orthoptists and medical practitioners in the comprehensive eye examination of children seen in an orthoptist-led triage clinic. Patient records over a 6-month period were retrospectively reviewed. Those with a presenting complaint related to vision or ocular motility were triaged into the orthoptist-led clinic and included in the study. Patients who did not meet the triage protocol and those who were not assessed by a medical practitioner at a subsequent appointment were excluded from analysis. The clinical findings from the orthoptist and medical practitioner were collected and compared. In total, sixty-three patients were reviewed during the 6-month period and met the inclusion criteria. After the initial comprehensive eye examination with an orthoptist, thirty-two were discharged from hospital and thirty-one were asked to return for a review appointment with a medical practitioner. Agreement between the orthoptists and medical practit...

Mata adalah cerminan jiwa, demikian kata pepatah. Sehingga tidak ada salah jika kita membahas secara tuntas anatomi dan fisiologi mata. Anatomi dan fisiologi mata perlu diketahui lebih dalam, untuk mempelajari lebih lanjut kelainan-kelanainan yang biasa diderita yang berkaitan dengan kelainan pada mata.

The visual outcomes for infants 18 months or younger with cataracts have improved dramatically over the past couple of decades. Earlier detection of infantile cataract and prompt surgical removal-with subsequent visual rehabilitation with contact lenses-mean that these patients now have a much better visual prognosis. Advances in contact lens technology have led to a significantly higher success rate with contact lenses and this has been a major factor in improving the visual outcomes for aphakic infants. This review outlines the contact lens management of infantile cataract, including a detailed analysis of the various contact lens options available and a discussion regarding the important factors that can cause issues with contact lens wear and affect the overall visual rehabilitation of the infant.

Background: Standard clinical treatment methods for amblyopia penalize the non-amblyopic eye, with subsequent compliance problems, and do not address the binocular vision abnormality. The purpose of this study is to evaluate a novel approach to amblyopia

The fundamental concept in the emerging field of rehabilitation and brain plasticity is that although there is much constancy in brain function and organization across our lifetime, there is remarkable variability as well. This variability reflects the brain's capacity to alter its structure and function in reaction to environmental diversity as well as to perturbations including injury throughout the lifespan. Although the term brain plasticity is now widely used, it is not easily defined and is used to refer to changes at many levels in the nervous system ranging from molecular events, such as changes in gene expression, to behavior (e.g., Shaw & McEachern (Eds.) [2001]. Toward a Theory of Neuroplasticity. Philadelphia, USA: Psychology Press). The focus of our work has been to correlate changes in behavior, neuronal morphology, and the organization of motor maps after cortical injury throughout the lifespan. In this article, we review evidence we have collected from a rat model of normal development and the effects of brain injury, and comment on the general principals that may apply to human stroke and amblyopia.

Background: Selective serotonin reuptake inhibitors (SSRIs) have been shown to enhance visual cortex plasticity in adult animals (Maya-Vetencourt, Sale et al. 2008). The aim of this study was to assess whether SSRIs increase visual cortex plasticity in humans. Methods: To test healthy visual plasticity, in the first experiment, participants (n = 20) with normal vision were randomized to a three-week course of fluoxetine or placebo. During drug administration, participants were trained on a motion discrimination task at a fixed motion direction. Learning was assessed for the trained motion direction and an untrained direction with and without a single dose of the benzodiazepine triazolam. Motor and visual cortex excitability was assessed using transcranial magnetic stimulation. In the second experiment, adults with amblyopia (n = 7) participated in a crossover study whereby placebo and citalopram were each combined with two weeks of occlusion therapy. Visual acuity (VA), stereopsis, electroretinograms and visual evoked potentials (VEPs) were measured fortnightly. The third experiment was a case study in which one participant with amblyopia completed two sessions of binocular training, one with placebo and the other with citalopram. Results: In the first experiment there was no effect of fluoxetine on learning or cortical excitability. However, triazolam significantly impaired performance for the untrained but not the trained motion direction. In the second experiment, there were no significant differences between citalopram and placebo for any of the outcome measures. However, three patients experienced VA improvements of over 0.1 Log MAR when treated with citalopram but not with placebo. Citalopram did not enhance the effects of binocular treatment for the single case tested. Conclusion: Fluoxetine did not affect visual cortex plasticity in normal observers. However, separate learning mechanisms were unveiled; as the untrained, but not the trained, task was affected by triazolam. Citalopram combined with occlusion may allow for VA improvements in some patients with amblyopia, however longer treatment durations may be required to improve visual functions in a larger number of patients. Preliminary data from one patient suggest that citalopram does not enhance the effects of binocular amblyopia treatment.

The purpose of this study was to evaluate the difference between full chart, single line, and single optotypes visual acuity (VA) test results in healthy and amblyopic children. Methods: Thirty-five children with amblyopia (20 with strabismus and 15 with anisometropia) and 40 ophthalmologically normal age-matched children were examined. The mean age of the patients in the study and control groups did not differ significantly (P = .9). A commercial projector that projected tumbling-E randomly placed optotypes was used. The VA of the amblyopic eye of the patients in the study group and the right eye of the patients in the control group was examined first using a full chart of optotypes, then using a single line of optotypes, and finally with individual symbols. The procedure was repeated with the other eye. Results: LogMAR VA improved when the full chart was substituted with a single line, and improved by a similar increment further with single optotypes, in both the study and control groups. VA improved significantly more in eyes with amblyopia than in control subjects. Results were not influenced by age. Conclusion: VA testing using a single line gives better, sometimes misleading results, than tests with a full chart because it reduces but does not eliminate the crowding effect. When using a device that can employ more than 1 mode, the exact test mode should be specified and maintained throughout the follow-up. (J AAPOS 1999;3:94-7)

To identify children with isoametropic amblyopia due to moderate to high hyperopia and evaluate associated findings and visual acuity outcome.Charts from two university's pediatric ophthalmology clinics were reviewed retrospectively. Healthy children with ≥+4.5 D spherical equivalent who did not have anisometropia ≥ 1.5 D were selected for data collection. The charts of qualifying children with bilateral amblyopia (visual acuity of 20/40 or less) were further analyzed.Identified were 418 children with the above set of criteria for hyperopia; 36 of these children had isoametropic amblyopia (bilateral amblyopia). This gives an estimated prevalence of isoametropic amblyopia of 8.6% in children with at least 4.5 D of hyperopia in one or both eyes. The children with isoametropic amblyopia presented at a later age (5 years, 1 month) than the overall group of hyperopes (3 years, 5 months). Strabismus was less prevalent in this group (64%) than in the entire population of children with high hyperopia (81%). These children's amblyopia responded well to treatment with glasses, and patching in 13 (36%) cases. Surgical intervention for residual strabismus was necessary in very few cases (2 of 36, 5.5%).Children with hyperopia ≥ 4.5 D have an increased risk of amblyopia and strabismus that further threatens their future visual function. Isoametropic amblyopia is a real risk in these children. Based on these results, hyperopic correction should be prescribed for children with ≥4.5 D of hyperopia even if no strabismus or fixation preference is detected, to reduce this risk. Screening programs should also be in place to identify these children at an early age.