Acuity In Amblyopic Eye Research Articles

Quantitative Measurement of Interocular Suppression in Anisometropic Amblyopia: A Case-Control Study

The aims of this study were to assess (1) the relationship between interocular suppression and visual function in patients with anisometropic amblyopia, (2) whether suppression can be simulated in matched controls using monocular defocus or neutral density filters, (3) the effects of spectacle or rigid gas-permeable contact lens correction on suppression in patients with anisometropic amblyopia, and (4) the relationship between interocular suppression and outcomes of occlusion therapy. Case-control study (aims 1-3) and cohort study (aim 4). Forty-five participants with anisometropic amblyopia and 45 matched controls (mean age, 8.8 years for both groups). Interocular suppression was assessed using Bagolini striated lenses, neutral density filters, and an objective psychophysical technique that measures the amount of contrast imbalance between the 2 eyes that is required to overcome suppression (dichoptic motion coherence thresholds). Visual acuity was assessed using a logarithm minimum angle of resolution tumbling E chart and stereopsis using the Randot preschool test. Interocular suppression assessed using dichoptic motion coherence thresholds. Patients exhibited significantly stronger suppression than controls, and stronger suppression was correlated significantly with poorer visual acuity in amblyopic eyes. Reducing monocular acuity in controls to match that of cases using neutral density filters (luminance reduction) resulted in levels of interocular suppression comparable with that in patients. This was not the case for monocular defocus (optical blur). Rigid gas-permeable contact lens correction resulted in less suppression than spectacle correction, and stronger suppression was associated with poorer outcomes after occlusion therapy. Interocular suppression plays a key role in the visual deficits associated with anisometropic amblyopia and can be simulated in controls by inducing a luminance difference between the eyes. Accurate quantification of suppression using the dichoptic motion coherence threshold technique may provide useful information for the management and treatment of anisometropic amblyopia. Proprietary or commercial disclosure may be found after the references.

Clinical Translation of Recommendations from Randomized Clinical Trials on Patching Regimen for Amblyopia

To investigate whether the evidence-based recommendations by the Pediatric Eye Disease Investigator Group (PEDIG) as initial treatment of amblyopia have been implemented into clinical practice and to discuss the necessary steps in translating evidence-based knowledge to inform clinical decision making. Retrospective cohort study. Children with amblyopia seen from 2007 through 2009 by academic and community ophthalmologists in a large urban center in North America that serves a population of more than 8 million. Using PEDIG criteria, moderate amblyopia was defined as visual acuity between 20/40 and 20/80 and severe amblyopia was defined as visual acuity between 20/100 and 20/400. Patching of the sound eye. The number of prescribed patching hours daily and the amblyopic eye visual acuity expressed as logarithm of the minimum angle of resolution (logMAR). For moderate amblyopia, the cohort (n = 71) was prescribed a mean of 3.2 hours of daily patching (95% confidence interval [CI]: 2.8-3.6 hours), which is significantly greater than the recommended 2 hours of daily patching for initial treatment. Only 24% (95% CI, 16%-35%) of them were prescribed the recommended initial patching hours. The amblyopic eye acuity on the 3- to 6-month visit in the cohort (0.23 logMAR) was similar to that of the 4-month visit in the PEDIG cohort (0.24 logMAR; P = 0.74). For severe amblyopia, the cohort (n = 52) was prescribed a mean of 3.9 hours of daily patching (95% CI, 3.5-4.3 hours), which is significantly lower than the recommended 6 hours of daily patching for initial treatment. Only 12% (95% CI, 5%-23%) of them were prescribed the recommended initial patching hours. The amblyopic eye acuity at the 7- to 12-month visit in the cohort (0.44 logMAR) was comparable with that of the 4-month visit in the PEDIG cohort (0.40 logMAR; P = 0.35). The evidence-based recommendations for amblyopia management have not been translated widely into changes in clinical practice in a large urban center in North America, although there is a general move from full-time to part-time patching since the PEDIG results were published. Using a well-established framework for knowledge translation, the Knowledge-to-Action Cycle, the necessary steps required to implement new knowledge into actual clinical practice are discussed.

Stereoacuity in children with anisometropic amblyopia

To determine factors associated with pretreatment and posttreatment stereoacuity in subjects with moderate anisometropic amblyopia. Data for subjects enrolled in seven studies conducted by the Pediatric Eye Disease Investigator Group were pooled. The sample included 633 subjects aged 3 to <18 years with anisometropic amblyopia, no heterotropia observed by cover test, and baseline amblyopic eye acuity of 20/100 or better. A subset included 248 subjects who were treated with patching or Bangerter filters and had stereoacuity testing at both the baseline and outcome examinations. Multivariate regression models identified factors associated with baseline stereoacuity and with outcome stereoacuity as measured by the Randot Preschool Stereoacuity test. Better baseline stereoacuity was associated with better baseline amblyopic eye acuity (P < 0.001), less anisometropia (P = 0.03), and anisometropia due to astigmatism alone (P < 0.001). Better outcome stereoacuity was associated with better baseline stereoacuity (P < 0.001) and better amblyopic eye acuity at outcome (P < 0.001). Among 48 subjects whose amblyopic eye visual acuity at outcome was 20/25 or better and within one line of the fellow eye, stereoacuity was worse than that of children with normal vision of the same age. In children with anisometropic amblyopia of 20/40 to 20/100 inclusive, better posttreatment stereoacuity is associated with better baseline stereoacuity and better posttreatment amblyopic eye acuity. Even if their visual acuity deficit resolves, many children with anisometropic amblyopia have stereoacuity worse than that of nonamblyopic children of the same age.

Optical Treatment of Strabismic and Combined Strabismic–Anisometropic Amblyopia

To determine visual acuity improvement in children with strabismic and combined strabismic-anisometropic (combined-mechanism) amblyopia treated with optical correction alone and to explore factors associated with improvement. Prospective, multicenter, cohort study. We included 146 children 3 to <7 years old with previously untreated strabismic amblyopia (n = 52) or combined-mechanism amblyopia (n = 94). Optical treatment was provided as spectacles (prescription based on a cycloplegic refraction) that were worn for the first time at the baseline visit. Visual acuity with spectacles was measured using the Amblyopia Treatment Study HOTV visual acuity protocol at baseline and every 9 weeks thereafter until no further improvement in visual acuity. Ocular alignment was assessed at each visit. Visual acuity 18 weeks after baseline. Overall, amblyopic eye visual acuity improved a mean of 2.6 lines (95% confidence interval [CI], 2.3-3.0), with 75% of children improving ≥ 2 lines and 54% improving ≥ 3 lines. Resolution of amblyopia occurred in 32% (95% CI, 24%-41%) of the children. The treatment effect was greater for strabismic amblyopia than for combined-mechanism amblyopia (3.2 vs 2.3 lines; adjusted P = 0.003). Visual acuity improved regardless of whether eye alignment improved. Optical treatment alone of strabismic and combined-mechanism amblyopia results in clinically meaningful improvement in amblyopic eye visual acuity for most 3- to <7-year-old children, resolving in at least one quarter without the need for additional treatment. Consideration should be given to prescribing refractive correction as the sole initial treatment for children with strabismic or combined-mechanism amblyopia before initiating other therapies. The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Quantitative measurement of interocular suppression in children with amblyopia

Previously it has been shown that intensive training aimed at reducing interocular suppression leads to improvement in amblyopic eye acuity as well as binocular vision in adults with strabismic amblyopia (Hess et al., 2010). In the current study we explored the possibility of using this approach to measure interocular suppression in children with amblyopia. We compared children (8–12 years old) with unilateral anisometropic and/or strabismic amblyopia to age-matched control children with normal visual acuity and no ocular pathology. Visual acuity was measured using the Regan high contrast chart; stereopsis was evaluated using the Randot preschool and the Randot circles test. Motion coherence thresholds for left-right direction discrimination were determined using a binocular global motion stimulus presented with virtual reality goggles (eMagin). The proportion of signal dots among noise dots was varied with a staircase procedure. In dichoptic viewing, high contrast signal dots were presented to the amblyopic eye (one eye of control subjects) while low contrast noise dots were presented to the fellow eye (the other eye of control subjects) at the motion coherence threshold. The contrast of the noise dots was increased until performance reached chance levels. Higher contrast thresholds indicated less interocular suppression. Regardless of their stereo acuity, all children in the amblyopic group exhibited some degree of binocular function on the dichoptic motion task. The amount of interocular suppression was high in the strabismic group and low in the anisometropic group indicating that interocular suppression is more potent in strabismic than in anisometropic amblyopia (Harrad and Hess, 1992). We have shown that the Hess et al stimuli can be used to measure both interocular suppression and residual binocular function in children with amblyopia. Interocular suppression is an established mechanism for visual loss in strabismic amblyopia; our results suggest it is less of a problem in anisometropic amblyopia.

Distance versus near visual acuity in amblyopia

There are conflicting reports about whether distance and near visual acuity are similar in eyes with amblyopia. The purpose of this study is to compare monocular distance visual acuity with near visual acuity in amblyopic eyes of children. Subjects 2 to 6 years of age were evaluated in a randomized trial of amblyopia therapy for moderate amblyopia (20/40 to 20/80) due to anisometropia, strabismus, or both. Prior to initiating the protocol-prescribed therapy, subjects had best-corrected visual acuity measured with standardized protocols at 3 meters and 0.4 meters using single-surrounded HOTV optotypes. A total of 129 subjects were included. The mean amblyopic eye visual acuity was similar at distance and near (mean, 0.45 logMAR at distance versus 0.45 logMAR at near; mean difference, +0.00, 95% CI, -0.03 to 0.03). Of the 129 subjects, 86 (67%) tested within 1 line at distance and near; 19 (15%) tested more than 1 logMAR line better at distance, and 24 (19%) tested more than 1 logMAR line better at near. The mean visual acuity difference between distance and near did not differ by cause of amblyopia, age, or spherical equivalent refractive error. We found no systematic difference between distance and near visual acuity in 2- to 6-year-old children with moderate amblyopia associated with strabismus and/or anisometropia. Individual differences between distance and near visual acuity are likely due to test-retest variability.

Effect of Age on Response to Amblyopia Treatment in Children

To determine whether age at initiation of treatment for amblyopia influences the response among children 3 to less than 13 years of age with unilateral amblyopia who have 20/40 to 20/400 amblyopic eye visual acuity. A meta-analysis of individual subject data from 4 recently completed randomized amblyopia treatment trials was performed to evaluate the relationship between age and improvement in logMAR amblyopic eye visual acuity. Analyses were adjusted for baseline amblyopic eye visual acuity, spherical equivalent refractive error in the amblyopic eye, type of amblyopia, prior amblyopia treatment, study treatment, and protocol. Age was categorized (3 to <5 years, 5 to <7 years, and 7 to <13 years) because there was a nonlinear relationship between age and improvement in amblyopic eye visual acuity. Children from 7 to less than 13 years of age were significantly less responsive to treatment than were younger age groups (children from 3 to <5 years of age or children from 5 to <7 years of age) for moderate and severe amblyopia (P < .04 for all 4 comparisons). There was no difference in treatment response between children 3 to less than 5 years of age and children 5 to less than 7 years of age for moderate amblyopia (P = .67), but there was a suggestion of greater responsiveness in children 3 to less than 5 years of age compared with children 5 to less than 7 years of age for severe amblyopia (P = .09). Amblyopia is more responsive to treatment among children younger than 7 years of age. Although the average treatment response is smaller in children 7 to less than 13 years of age, some children show a marked response to treatment.

Near compared with distance visual acuity in amblyopic eyes

Near compared with distance visual acuity in amblyopic eyes

Effect and sustainability of part-time occlusion therapy for patients with anisometropic amblyopia aged ≥8 years

AimsTo study the effect and long-term sustainability of part-time occlusion therapy for anisometropic amblyopia after 8 years of age.MethodsA total of 41 anisometropic amblyopes aged ≥8 years were analysed. In...

A Randomized Trial Comparing Bangerter Filters and Patching for the Treatment of Moderate Amblyopia in Children

To determine whether visual acuity improvement with Bangerter filters is similar to improvement with patching as initial therapy for children with moderate amblyopia. Randomized, clinical trial. We enrolled 186 children, 3 to <10 years old, with moderate amblyopia (20/40-20/80). Children were randomly assigned to receive either daily patching or to use a Bangerter filter on the spectacle lens in front of the fellow eye. Study visits were scheduled at 6, 12, 18, and 24 weeks. Visual acuity in amblyopic eyes at 24 weeks. At 24 weeks, amblyopic eye improvement averaged 1.9 lines in the Bangerter group and 2.3 lines in the patching group (difference in mean visual acuities between groups adjusted for baseline acuity = 0.38 line). The upper limit of a 1-sided 95% confidence interval was 0.76 line, which slightly exceeded a prespecified noninferiority limit of <0.75 line. Similar percentages of subjects in each group improved > or =3 lines (Bangerter group 38% vs patching group 35%; P = 0.61) or had > or =20/25 amblyopic eye acuity (36% vs 31%, respectively; P = 0.86). There was a lower treatment burden in the Bangerter group as measured with the Amblyopia Treatment Index. With Bangerter filters, neither a fixation switch to the amblyopic eye nor induced blurring in the fellow eye to worse than that of the amblyopic eye was required for visual acuity improvement. Because the average difference in visual acuity improvement between Bangerter filters and patching was less than half a line, and there was lower burden of treatment on the child and family, Bangerter filter treatment is a reasonable option to consider for initial treatment of moderate amblyopia.

Long-Term Visual Outcome Following Cessation of Occlusion Therapy in Unilateral Amblyopia

Purpose: To evaluate a long-term visual outcome following cessation of occlusion therapy in unilateral amblyopia. Methods: A total of 70 patients who successfully finished occlusion therapy (including maintenance therapy) for unilateral amblyopia and were followed up for at least 1 year after cessation of occlusion were retrospectively reviewed. Even after the success of occlusion therapy, maintenance therapy or regular examinations were performed until the visual development of the normal fellow eye (NE) was completed. The recurrence of amblyopia was defined as a 2 or more logarithm of the minimum angle of resolution (LogMAR) levels of visual acuity (VA) reduction of the amblyopic eye (AE), as compared to the NE, at the last evaluation. Results: Amblyopia was associated with strabismus in 19 patients, anisometropia in 33 patients, and both in 39 patients. The mean age at the cessation of occlusion and at the last evaluation was 7.7 1.9 years and 11.4 2.9 years, respectively. The mean VA of the AE was 0.01 0.03 and mean stereopsis was 101.7 87.5 seconds of arc at the cessation of occlusion, and both improved at the last evaluation. However, the improvement of mean VA of the AE was not statistically significant (p = 0.21). The mean duration of maintenance therapy was 25.6 21.0 months, and was 3 times longer than the duration required to achieve success in the treatment of amblyopia. At the last evaluation, the recurrence of amblyopia was not found, while 3 patients (4.3%) lost 1 LogMAR level of VA in the AE, as compared to the NE. Conclusions: Visual outcome following successful cessation of occlusion therapy for unilateral amblyopia was favorable without recurrence of amblyopia.

The Teller Acuity Cards Are Effective in Detecting Amblyopia

Detection of amblyopia in infants and toddlers is difficult because the current clinical standard for this age group, fixation preference, is inaccurate. Although grating acuity represents an alternative, studies of preschoolers and schoolchildren report that it is not equivalent to the gold standard optotype acuity. Here, we examine whether the Teller Acuity Cards (TAC) can detect amblyopia effectively by testing children old enough (7.8 +/- 3.6 years) to complete optotype acuity testing. Grating acuity was assessed monocularly in 45 patients with unilateral amblyopia, 44 patients at risk for amblyopia, and 37 children with no known vision disorders. Each child's grating acuity was classified as normal/abnormal based on age-appropriate norms. These classifications were compared with formal amblyopia diagnoses. Grating acuity was finer than optotype acuity among amblyopic eyes (medians: 0.28 vs. 0.40 logMAR, respectively, p < 0.0001) but not among fellow eyes (medians: 0.03 vs. 0.10 logMAR, respectively, p = 0.36). The optotype acuity-grating acuity discrepancy among amblyopic eyes was larger for cases of severe amblyopia than for moderate amblyopia (means: 0.64 vs. 0.18 logMAR, respectively, p = 0.0001). Nevertheless, most cases of amblyopia were detected successfully by the TAC, yielding a sensitivity of 80%. Furthermore, grating acuity was relatively sensitive to all amblyopia subtypes (69 to 89%) and levels of severity (79 to 83%). Although grating acuity is finer than optotype acuity in amblyopic eyes, most children with amblyopia were identified correctly suggesting that grating acuity is an effective clinical alternative for detecting amblyopia.

Pharmacological Plus Optical Penalization Treatment for Amblyopia

To compare weekend atropine sulfate use augmented by a plano lens for the sound eye with weekend atropine use alone for moderate amblyopia in children aged 3 years to younger than 7 years.In a multicenter clinical trial, 180 children with moderate amblyopia (visual acuities of 20/40-20/100) were randomized to weekend atropine use augmented by a plano lens or weekend atropine use alone.Masked assessment of amblyopic eye visual acuity using the Amblyopia Treatment Study HOTV testing protocol at 18 weeks.At 18 weeks, amblyopic eye improvement averaged 2.8 lines in the group that received atropine plus a plano lens and 2.4 lines in the group that received atropine alone (mean difference between groups adjusted for baseline acuity, 0.3 line; 95% confidence interval, -0.2 to 0.8 line). Amblyopic eye visual acuity was 20/25 or better in 24 patients (29%) in the group that received atropine only and 35 patients (40%) in the group that received atropine plus a plano lens (P = .03). More patients in the group that received atropine plus a plano lens had reduced sound eye visual acuity at 18 weeks; however, there were no cases of persistent reverse amblyopia.As an initial treatment for moderate amblyopia, the augmentation of weekend atropine use with a plano lens does not substantially improve amblyopic eye visual acuity when compared with weekend atropine use alone. Application to Clinical Practice Treatment of children with unilateral amblyopia. Trial Registration clinicaltrials.org Identifier: NCT00315302.

A Randomized Trial of Near Versus Distance Activities While Patching for Amblyopia in Children Aged 3 to Less Than 7 Years

To determine whether performing near activities while patching for amblyopia enhances improvement in visual acuity. Randomized clinical trial. A total of 425 children, aged 3 to <7 years, with amblyopia (20/40-20/400) that was caused by anisometropia, strabismus, or both, and that persisted after treatment with spectacles. Children were randomized to 2 hours of patching per day with near activities or 2 hours of patching per day with distance activities. Instruction sheets describing common near and distance activities were given to the parents. Study visits were scheduled at 2, 5, 8, and 17 weeks. In weeks without a visit, weekly telephone calls were made to the parent to monitor and encourage compliance during the first 8 weeks. Masked assessment of visual acuity by isolated crowded HOTV optotypes at 8 weeks. At 8 weeks, improvement in amblyopic eye visual acuity averaged 2.6 lines in the distance activities group and 2.5 lines in the near activities group (mean difference in acuity between groups, adjusted for baseline acuity, 0.0 lines 95% confidence interval, -0.3 to 0.3). The 2 groups also appeared statistically similar at the 2-, 5-, and 17-week visits. At the 17-week examination, children with severe amblyopia improved a mean of 3.6 lines with 2 hours of daily patching. Performing common near activities does not improve visual acuity outcome when treating anisometropic, strabismic, or combined amblyopia with 2 hours of daily patching. Children with severe amblyopia may respond to 2 hours of daily patching.

The effect of colored crowding bars on the HOTV visual acuity test in amblyopic patients

Colored versus black crowding bars surrounding a black optotype may induce a greater level of interest in visual acuity testing in young children. To evaluate the adequacy of colored bars for a satisfactory crowding effect in children with amblyopia, we compared visual acuity measurements using black versus red, green, or yellow bars. To choose the best color to compare with black, 53 patients with amblyopia were randomly assigned to 1 of 3 crowding bar colors. Subjects had the visual acuity of each eye measured with black HOTV optotypes and bars and then with black optotypes and either red, green, or yellow bars. In a second phase of the study red crowding bars were compared with black in a group of 48 different patients with amblyopia. The difference in logMAR visual acuity between amblyopic eyes tested with red versus black crowding bars was not statistically significant (mean visual acuities of -0.24 and -0.26, respectively; p = 0.315), but the difference was significant with either green (-0.30 and -0.34; p = 0.047) or yellow (-0.14 and -0.24; p = 0.0003). In the nonamblyopic eyes none of the colored crowding bars yielded significantly different visual acuity measurements compared with black. In the second phase of the study red crowding bars yielded an average of one letter worse visual acuity than black bars, but the difference was not statistically significant. Red crowding bars surrounding black optotypes are an acceptable alternative to black crowding bars for the measurement of visual acuity in amblyopic eyes.

Comparison of the visual effects of Fresnel prisms in normal and amblyopic eyes

To assess the effects of Fresnel prisms on visual acuity and peak contrast sensitivity in the amblyopic and sound eyes of participants with amblyopia and to determine whether these functions were affected by Fresnel prisms to a different degree than those of controls. The LogMAR visual acuity and peak contrast sensitivity of 10 unilateral amblyopic participants (mean age, 22.6 years) and 9 controls (mean age, 26.2 years) were tested with Fresnel prisms of powers 5(Delta), 10(Delta), 15(Delta), 20(Delta), and 25(Delta) and without a Fresnel prism. A statistically significant reduction in visual acuity with increasing prism power was found for all 3 groups, with the visual acuity of the amblyopic eyes being the least affected by the prisms. No statistically significant differences were found between the control and the sound eyes. No statistically significant differences in the effects of the prisms on peak contrast sensitivity could be detected between the 3 groups. Fresnel prisms were found to have a smaller effect on those amblyopic eyes with a poorer baseline visual acuity, indicating that these eyes may tolerate strong prisms without substantially impairing their visual acuity. Fresnel prisms have a lesser effect on the visual acuity of amblyopic eyes than on controls. In contrast, results for peak contrast sensitivity were very similar for each of the groups tested, and no significant differences were evident between the amblyopic, sound, and control eyes.

The Prospective Comparison of the Efficacy of Intermittent Atropine Penalization and Part-time Occlusion Therapy

Purpose: The objective of this study was to compare prospectively the efficacy between intermittent atropine penalization and part-time occlusion therapy for amblyopia in patients younger than 10 years old. Methods: The patients with newly diagnosed amblyopia were randomly assigned to either atropine penalization (Group A) or occlusion therapy (Group O). One drop of atropine was instilled into the sound eyes of patients in group A twice per week, while each patient in group O underwent daily patching for 6 hours in their sound eyes. The minimum follow-up time was 3 months after treatment. Best corrected visual acuity and compliance were compared for both groups. Results: A total of 43 patients were enrolled in this study, with 18 assigned to group A and 25 to group O. The follow-up period was not significantly different between group A and group O (6.3 and 7.0 months, respectively; p=0.437). The final corrected visual acuity (LogMAR) scores of amblyopic eyes in both groups showed significant improvement in the visual acuity of amblyopic eyes compared with that at baseline (0.28 in group A and 0.19 in group O). Group A had a higher level of compliance than group O (97.0 and 91.5%, respectively; p=0.007). There was no difference in the groups with regard to visual acuity in amblyopic eyes, which showed similar improvement (3.5:3.4 lines, respectively; p=0.867). Conclusions: This study shows that for treating amblyopia in children younger than 10 years old, intermittent atropine penalization seems to be as effective as part-time occlusion. J Korean Ophthalmol Soc 49(6):958-966, 2008

Optic Disc Area and Retinal Area in Amblyopia

Purpose: To compare retinal area to optic disc rim area ratios of hyperopic normal, strabismic eyes with equal acuity, amblyopic, and fellow eyes. Methods: Neuroretinal rim areas of 293 amblyopic and fellow eyes, and 77 non-amblyopic hyperopic right eyes, and 84 non-amblyopic strabismic right eyes were measured by magnification corrected retinal photography and planimetry. Retinal area estimates were based on axial lengths. Inclusion criteria: All subjects had bilateral hyperopia. Patients with glaucoma or known optic nerve atrophy were excluded. The normal and strabismic groups had equal visual acuity in each eye better than 20/40. The amblyopic group had acuity worse than 20/40 in one eye uncorrectable with lenses and without gross anatomic defects. Results: The amblyopic group included 137 with strabismus and 89 with anisometropia exceeding 1.5 diopters. There were highly significant differences between the ratio of retinal area to optic disc rim area of the amblyopic and of normal eyes (unpaired t-test, p = 8.6 × 10-6), the amblyopic and strabismic right eyes (unpairedt−test, p = 4.22 × 10-8) as well between the fellow and amblyopic eyes (pairedt−test, p = 2.13 × 10-5). The difference between the normal and strabismic eyes without amblyopia was not significant (p = 0.82). There was a 20 percent increase in the retinal receptor areas of hyperopic amblyopic eyes as compared to hyperopic eyes without amblyopia despite reduced retinal areas in the amblyopic eyes. Dysplastic and/or asymmetric optic discs were present in 163 of 293 (56 percent) amblyopic patients, 47 of 84 (56 percent) strabismic, and 10 of 77 (13 percent) normal patients. Conclusions: The increase in the receptor area may be an explanation for diminished acuity and impaired visual function in amblyopic eyes.

Effect of oral CDP-choline on visual function in young amblyopic patients

The purpose of the study was to evaluate the effect on visual function of orally administered CDP-choline in addition to patching for the treatment of amblyopia in children. This was an open label parallel group study comparing patching plus oral CDP-choline with patching alone. Sixty-one participants (aged between 5 and 10 years) suffering from anisometropic or strabismic amblyopia were divided at random into two groups: Group A, 800 or 1,200 mg (according to the body weight) of orally administered CDP-choline and 2-h patching a day; Group B, 2-h patching a day. Both groups were treated for 30 consecutive days. A follow-up visit was set 60 days after the treatment was discontinued. The main outcome measure was the change in visual acuity of amblyopic eyes as measured by Snellen's E charts. The secondary outcome measures were changes in the visual acuity of amblyopic eye as measured by isolated letters (Snellen's E) and changes in the contrast sensitivity of amblyopic eyes. The addition of CDP-choline to patching therapy was not found to be more effective than patching alone after 30-day treatment. The present results showed that adding CDP-choline to patching stabilised the effects obtained during the treatment period. In fact, whereas the participants treated only with patching showed a decrease in visual acuity at 90 days, these receiving CDP-choline and patching combined appeared to maintain the results obtained (two-way ANOVA: P = 0.0042). Similar results were obtained when measuring visual acuity by isolated Snellen's E letters. In amblyopic patients, CDP-choline combined with patching contributes to obtaining more stable effects than patching alone.

Amblyopia and Strabismus Questionnaire (A&amp;SQ): clinical validation in a historic cohort

We recently developed the Amblyopia & Strabismus Questionnaire (A&SQ) to assess the quality of life in amblyopia and/or strabismus patients, and evaluated its content and criterion validity. The A&SQ was now validated clinically by correlating its outcome with past and current orthoptic parameters in a historic cohort of amblyopia and/or strabismus patients. The cohort was derived from all 471 patients who were treated by occlusion therapy in the Waterland Hospital in Purmerend between 1968 and 1974 and born between 1962 and 1972. All children with insufficient visual acuity from the Waterland area had been referred to a single ophthalmologist and orthoptist. Of these, 203 were traced, and 174 filled out the A&SQ. In 137 of these, binocular vision, visual acuity, and angle of strabismus were reassessed 30-35 years after occlusion therapy. These clinical parameters were correlated with the five A&SQ domains: "distance estimation", "visual disorientation", "fear of losing the better eye", "diplopia", and "social contact and cosmetic problems". The current acuity at distance of the amblyopic eye and reading acuity of the amblyopic eye correlated significantly with all five A&SQ domains (significance level P = 0.01-P = 0.05). Weaker correlations were found for binocularity. In spite of the expectation that stereopsis should strongly correlate with the domain "distance estimation", and angle of strabismus with the domain "social contact and cosmetic problems", the acuity of the amblyopic eye was the overall dominant parameter. The adult acuity of the amblyopic eye seems the most important clinical determinant for quality of life in amblyopia and/or strabismus patients, even in domains of distance estimation, visual disorientation, and social contact and cosmetic problems, although intermediate determinants cannot be excluded.