Acuity In Amblyopic Eye Research Articles

Effect of a Binocular iPad Game vs Part-time Patching in Children Aged 5 to 12 Years With Amblyopia

A binocular approach to treating anisometropic and strabismic amblyopia has recently been advocated. Initial studies have yielded promising results, suggesting that a larger randomized clinical trial is warranted. To compare visual acuity (VA) improvement in children with amblyopia treated with a binocular iPad game vs part-time patching. A multicenter, noninferiority randomized clinical trial was conducted in community and institutional practices from September 16, 2014, to August 28, 2015. Participants included 385 children aged 5 years to younger than 13 years with amblyopia (20/40 to 20/200, mean 20/63) resulting from strabismus, anisometropia, or both. Participants were randomly assigned to either 16 weeks of a binocular iPad game prescribed for 1 hour a day (190 participants; binocular group) or patching of the fellow eye prescribed for 2 hours a day (195 participants; patching group). Study follow-up visits were scheduled at 4, 8, 12, and 16 weeks. A modified intent-to-treat analysis was performed on participants who completed the 16-week trial. Binocular iPad game or patching of the fellow eye. Change in amblyopic-eye VA from baseline to 16 weeks. Of the 385 participants, 187 were female (48.6%); mean (SD) age was 8.5 (1.9) years. At 16 weeks, mean amblyopic-eye VA improved 1.05 lines (2-sided 95% CI, 0.85-1.24 lines) in the binocular group and 1.35 lines (2-sided 95% CI, 1.17-1.54 lines) in the patching group, with an adjusted treatment group difference of 0.31 lines favoring patching (upper limit of the 1-sided 95% CI, 0.53 lines). This upper limit exceeded the prespecified noninferiority limit of 0.5 lines. Only 39 of the 176 participants (22.2%) randomized to the binocular game and with log file data available performed more than 75% of the prescribed treatment (median, 46%; interquartile range, 20%-72%). In younger participants (aged 5 to <7 years) without prior amblyopia treatment, amblyopic-eye VA improved by a mean (SD) of 2.5 (1.5) lines in the binocular group and 2.8 (0.8) lines in the patching group. Adverse effects (including diplopia) were uncommon and of similar frequency between groups. In children aged 5 to younger than 13 years, amblyopic-eye VA improved with binocular game play and with patching, particularly in younger children (age 5 to <7 years) without prior amblyopia treatment. Although the primary noninferiority analysis was indeterminate, a post hoc analysis suggested that VA improvement with this particular binocular iPad treatment was not as good as with 2 hours of prescribed daily patching. http://www.clinicaltrials.gov Identifier: NCT02200211.

Assessing Suppression in Amblyopic Children With a Dichoptic Eye Chart.

PurposeSuppression has a key role in the etiology of amblyopia, and contrast-balanced binocular treatment can overcome suppression and improve visual acuity. Quantitative assessment of suppression could have a role in managing amblyopia. We describe a novel eye chart to assess suppression in children.MethodsWe enrolled 100 children (7–12 years; 63 amblyopic, 25 nonamblyopic with strabismus or anisometropia, 12 controls) in the primary cohort and 22 children (3–6 years; 13 amblyopic, 9 nonamblyopic) in a secondary cohort. Letters were presented on a dichoptic display (5 letters per line). Children wore polarized glasses so that each eye saw a different letter chart. At each position, the identity of the letter and its contrast on each eye's chart differed. Children read 8 lines of letters for each of 3 letter sizes. The contrast balance ratio was the ratio at which 50% of letters seen by the amblyopic eye were reported.ResultsAmblyopic children had significantly higher contrast balance ratios for all letter sizes compared to nonamblyopic children and controls, requiring 4.6 to 5.6 times more contrast in the amblyopic eye compared to the fellow eye (P < 0.0001). Amblyopic eye visual acuity was correlated with contrast balance ratio (r ranged from 0.49–0.57 for the 3 letter sizes). Change in visual acuity with amblyopia treatment was correlated with change in contrast balance ratio (r ranged from 0.43–0.62 for the 3 letter sizes).ConclusionsSeverity of suppression can be monitored as part of a routine clinical exam in the management of amblyopia in children.

Binocular treatment of amblyopia using videogames (BRAVO): study protocol for a randomised controlled trial.

BackgroundAmblyopia is a common neurodevelopmental disorder of vision that is characterised by visual impairment in one eye and compromised binocular visual function. Existing evidence-based treatments for children include patching the nonamblyopic eye to encourage use of the amblyopic eye. Currently there are no widely accepted treatments available for adults with amblyopia. The aim of this trial is to assess the efficacy of a new binocular, videogame-based treatment for amblyopia in older children and adults. We hypothesise that binocular treatment will significantly improve amblyopic eye visual acuity relative to placebo treatment.Methods/designThe BRAVO study is a double-blind, randomised, placebo-controlled multicentre trial to assess the effectiveness of a novel videogame-based binocular treatment for amblyopia. One hundred and eight participants aged 7 years or older with anisometropic and/or strabismic amblyopia (defined as ≥0.2 LogMAR interocular visual acuity difference, ≥0.3 LogMAR amblyopic eye visual acuity and no ocular disease) will be recruited via ophthalmologists, optometrists, clinical record searches and public advertisements at five sites in New Zealand, Canada, Hong Kong and Australia. Eligible participants will be randomised by computer in a 1:1 ratio, with stratification by age group: 7–12, 13–17 and 18 years and older. Participants will be randomised to receive 6 weeks of active or placebo home-based binocular treatment. Treatment will be in the form of a modified interactive falling-blocks game, implemented on a 5th generation iPod touch device viewed through red/green anaglyphic glasses. Participants and those assessing outcomes will be blinded to group assignment. The primary outcome is the change in best-corrected distance visual acuity in the amblyopic eye from baseline to 6 weeks post randomisation. Secondary outcomes include distance and near visual acuity, stereopsis, interocular suppression, angle of strabismus (where applicable) measured at baseline, 3, 6, 12 and 24 weeks post randomisation. Treatment compliance and acceptability will also be assessed along with quality of life for adult participants.DiscussionThe BRAVO study is the first randomised controlled trial of a home-based videogame treatment for older children and adults with amblyopia. The results will indicate whether a binocular approach to amblyopia treatment conducted at home is effective for patients aged 7 years or older.Trial registrationThis trial was registered in Australia and New Zealand Clinical Trials Registry (ACTRN12613001004752) on 10 September 2013.

Television Video Games in the Treatment of Amblyopia in Children Aged 4–7 Years

ABSTRACTAim: To investigate the role of television video games in childhood amblyopia treatment.Method: This prospective, randomized, interventional study included 40 patients between 4-7 years of age, with unilateral amblyopia (visual acuity in amblyopic eye between 1-0.6 LogMAR equivalents) attending the squint clinic at a tertiary eye hospital.All patients were prescribed optimal spectacle correction and occlusion therapy, i.e. full time patching according to patient’s age, was initiated after six weeks.; full-time patching according to patient’s age was initiated after 6 weeks. Subjects were randomly divided into two groups of 20 each. Patients in the first group, Group A (control), were prescribed patching alone. Patients in the second group, Group B (study), were made to play action video games, with the help of a commercial television set, along with patching. They attended 12 half-hour sessions each, at weekly intervals. Follow-up assessments included best corrected visual acuity (BCVA) (both distance and near) and stereoacuity measurements at 3, 6, 9, and 12 weeks.Results: The mean age of patients was 6.03 ± 1.14 years. The distance BCVA in the amblyopic eye showed a significant improvement at final follow-up (12 weeks) in both groups: from 0.84 ± 0.19 to 0.55 ± 0.21 LogMAReq in Group A and 0.89 ± 0.16 to 0.46 ± 0.22 LogMAReq in Group B. However, improvement in BCVA was significantly better in group B at all visits (P=0.002, 12 weeks). The study group also had a significantly better outcome in terms near visual acuity improvement (P = 0.006, 12 weeks). There was also greater stereoacuity improvement in group B, with 7 patients improving to 100 secs of arc or better.Conclusion: Video games supplemental to occlusion may be considered favorable for visual development in amblyopic children, and the study encourages further research on this subject.

A pilot randomized clinical trial of intermittent occlusion therapy liquid crystal glasses versus traditional patching for treatment of moderate unilateral amblyopia

To compare the effectiveness of intermittent occlusion therapy (IO therapy) using liquid crystal glasses and continuous occlusion therapy using traditional adhesive patches for treating amblyopia. Children 3-8years of age with previously untreated, moderate, unilateral amblyopia (visual acuity of 20/40 to 20/100 in the amblyopic eye) were enrolled in this randomized controlled trial. Amblyopia was associated with strabismus, anisometropia, or both. All subjects had worn any optimal refractive correction for at least 12weeks without improvement. Subjects were randomized into two treatment groups: a 4-hour IO therapy group with liquid crystal glasses (Amblyz), set at 30-second opaque/transparent intervals (occluded 50% of wear time), and a 2-hour continuous patching group (occluded 100% of wear time). For each patient, visual acuity was measured using ATS-HOTV before and after 12weeks of treatment. Data from 34 patients were available for analysis. Amblyopic eye visual acuity improvement from baseline was 0.15±0.12 logMAR (95% CI, 0.09-0.15) in the IO therapy group (n=19) and 0.15±0.11 logMAR (95% CI, 0.1-0.15) in the patching group (n=15). In both groups improvement was significant, but the difference between groups was not (P=0.73). No adverse effects were reported. In this pilot study, IO therapy with liquid crystal glasses is not inferior to adhesive patching and is a promising alternative treatment for children 3-8years of age with moderate amblyopia.

The effect of transcranial direct current stimulation on contrast sensitivity and visual evoked potential amplitude in adults with amblyopia.

Amblyopia is a neurodevelopmental disorder of vision that occurs when the visual cortex receives decorrelated inputs from the two eyes during an early critical period of development. Amblyopic eyes are subject to suppression from the fellow eye, generate weaker visual evoked potentials (VEPs) than fellow eyes and have multiple visual deficits including impairments in visual acuity and contrast sensitivity. Primate models and human psychophysics indicate that stronger suppression is associated with greater deficits in amblyopic eye contrast sensitivity and visual acuity. We tested whether transcranial direct current stimulation (tDCS) of the visual cortex would modulate VEP amplitude and contrast sensitivity in adults with amblyopia. tDCS can transiently alter cortical excitability and may influence suppressive neural interactions. Twenty-one patients with amblyopia and twenty-seven controls completed separate sessions of anodal (a-), cathodal (c-) and sham (s-) visual cortex tDCS. A-tDCS transiently and significantly increased VEP amplitudes for amblyopic, fellow and control eyes and contrast sensitivity for amblyopic and control eyes. C-tDCS decreased VEP amplitude and contrast sensitivity and s-tDCS had no effect. These results suggest that tDCS can modulate visual cortex responses to information from adult amblyopic eyes and provide a foundation for future clinical studies of tDCS in adults with amblyopia.

Amblyopic children read more slowly than controls under natural, binocular reading conditions

Recent evidence suggests that amblyopia results in fixation instability and atypical saccades. Reading is a vision-reliant ability that requires sequential eye movements, including forward and regressive saccades. This study investigated reading and associated eye movements in school-age amblyopic children. Amblyopic children with strabismus and/or anisometropia (n = 29) were compared to nonamblyopic children treated for strabismus (n = 23) and normal control children (n = 21). While fitted with the ReadAlyzer, an eye movement recording system, children silently read a grade-level paragraph of text during binocular viewing. Reading rate, number of forward and regressive saccades per 100 words, and fixation duration were determined. Comprehension was evaluated with a 10-item quiz; only data from children with at least 80% correct responses were included. Amblyopic children read more slowly and had more saccades compared with nonamblyopic children with treated strabismus and normal controls. Fixation duration did not differ significantly for amblyopic children versus normal controls. Treated strabismic children without amblyopia did not differ significantly from normal controls on any reading measure. Amblyopic eye visual acuity was not correlated with any reading measure. Amblyopia was associated with slower reading speed in school-age children. Treatment for monocular amblyopia visual acuity impairment could improve reading speed and efficiency.

Dichoptic movie viewing treats childhood amblyopia.

Contrast-balanced dichoptic experience with perceptual-learning tasks or simple games has been shown to improve visual acuity significantly in amblyopia. However, these tasks are intensive and repetitive, and up to 40% of unsupervised patients are noncompliant. We investigated the efficacy of a potentially more engaging movie method to provide contrast-balanced binocular experience via complementary dichoptic stimulation. Eight amblyopic children 4-10 years of age were enrolled in a prospective cohort study to watch 3 dichoptic movies per week for 2 weeks on a passive 3D display. Dichoptic versions of 18 popular animated feature films were created. A patterned image mask of irregularly shaped blobs was multiplied with the movie images seen by the amblyopic eye and an inverse mask was multiplied with the images seen by the fellow eye. Fellow-eye contrast was initially set at a reduced level that allowed binocular vision and was then incremented by 10% at each visit. Best-corrected visual acuity, random dot stereoacuity, and interocular suppression were measured at baseline and 2 weeks. Mean amblyopic eye visual acuity (with standard error of the mean) improved from a logarithm of minimum angle of resolution of 0.72 ± 0.08 at baseline to 0.52 ± 0.09 (P = 0.003); that is, 2.0 lines of improvement at the 2-week outcome visit. No significant change in interocular suppression or stereoacuity was found. Passive viewing of dichoptic feature films is feasible and could be a promising new treatment for childhood amblyopia. The maximum improvement that may be achieved by watching dichoptic movies remains to be determined. No known side effects are associated with this new treatment.

The repeatability of the Sbisa bar for testing density of suppression

Aim: The density of suppression is often assessed in children undergoing amblyopia treatment. The pur- pose of this study was to assess the repeatability of the Sbisa bar to measure density of suppression by the same and different observers. Methods: A prospective repeated measures study was performed on participants aged 5–16 years. Partici- pants with constant suppression due to strabismus had the Sbisa bar test performed twice by one observer and once by a second observer with a period of 15 minutes between each test. Results: Thirty participants were recruited with a mean age 7.3 years (range 5.1–15.1 years). Median filter value for the first test was 15 (interquartile range (IQR) 14–17), for the second test was 15 (IQR 13–17) and for the third test was 14 (IQR 13–17). Interclass correlation coefficient was 0.70 (95% CI 0.46 to 0.85) for the same observer and 0.73 (95% CI 0.44 to 0.87) for different observers. Inter-rater repeatability coefficient, k , was 0.32, SE 0.11 (95% CI 0.10 to 0.54). There was no correlation between the median filter value from the first observer’s tests with age ( R = 0.08), visual acuity in the amblyopic eye ( R = 0.01) or visual acuity difference ( R = 0.01). Conclusions: The results show that in patients with suppression > filter 10 the Sbisa bar is repeatable within one to three filters when assessed by the same or different observers. There is no correlation between density of suppression and visual acuity or age.

The effect of occlusion therapy on motion perception deficits in amblyopia

There is growing evidence for deficits in motion perception in amblyopia, but these are rarely assessed clinically. In this prospective study we examined the effect of occlusion therapy on motion-defined form perception and multiple-object tracking. Participants included children (3–10years old) with unilateral anisometropic and/or strabismic amblyopia who were currently undergoing occlusion therapy and age-matched control children with normal vision. At the start of the study, deficits in motion-defined form perception were present in at least one eye in 69% of the children with amblyopia. These deficits were still present at the end of the study in 55% of the amblyopia group. For multiple-object tracking, deficits were present initially in 64% and finally in 55% of the children with amblyopia, even after completion of occlusion therapy. Many of these deficits persisted in spite of an improvement in amblyopic eye visual acuity in response to occlusion therapy. The prevalence of motion perception deficits in amblyopia as well as their resistance to occlusion therapy, support the need for new approaches to amblyopia treatment.

Atropine vs Patching-Reply.

Dr. Lempert raises several issues, which we believe are mistaken or do not affect the interpretation of our results. As described,1 only subjects at sites with >5 enrolled children were eligible for long-term follow-up for logistical reasons, which reduced the proportion of the original cohort that was enrolled in the follow-up study. The 15-year examination was completed by 152 of 188 eligible participants (80.9%). We compared subjects who participated in follow-up with those who did not and noted in the manuscript that those who participated had slightly better visual acuity (VA) at two years than those who did not (20/25 versus 20/32), which could have resulted in a slight overestimate of visual acuity at age 15 years. In addition, 147 participants in Table 1 noted by Dr. Lempert were only those who completed the visit at 15 years of age and had VA tested with the E-ETDRS©.2 Five participants had VA tested with a method other than E-ETDRS and were not included in the primary results. Dr. Lempert also appears to have misread Table 1; 46.9% of fellow eyes had 20/20 or better at baseline (rather than 9.5% he cited, which was the proportion who had 20/16 or better). Nevertheless, we would expect some improvement in the measured VA of the fellow eye over more than 10 years of follow-up due to maturation. We believe that the mean interocular acuity differences (IOD) of 2.1 logMAR lines at 15 years of age and 2.0 logMAR lines at 10 years of age using E-ETDRS testing were greater than the mean IOD of 1.6 logMAR lines at the 2-year exam using the HOTV protocol due to the different methods for testing. In our report at 10 years of age that directly compared the 2 VA testing methods, we found that measured IOD was smaller with HOTV than with E-ETDRS.3 Regarding Dr. Lempert's question regarding the implications of including subjects with fellow eye visual acuity better than 20/20, we did not exclude such children because they are within the spectrum of moderate amblyopia. Their exclusion would have reduced the generalizability of our results and we see no reason why their inclusion would “skew the results.” We chose to include only children with amblyopic-eye visual acuity 20/40 to 20/100 in this trial,4 because when we designed the study, we were uncertain if atropine would be effective with visual acuity less than 20/100.5 (Subsequently atropine has been found to be effective for many cases of severe amblyopia.6) We agree that interpretation of the results should always be viewed in light of eligibility criteria, and we have carefully included that information in each report. Our primary message was that there was little loss of VA improvement after treatment was completed. Our long term follow-up data provide evidence that part-time patching and atropine drops are effective and long lasting treatments for many children, 3 to <7 years of age, who have anisometropic, strabismic or combined amblyopia.

Amblyopia and the binocular approach to its therapy

There is growing evidence that abnormal binocular interactions play a key role in amblyopia. In particular, stronger suppression of the amblyopic eye has been associated with poorer amblyopic eye visual acuity and a new therapy has been described that directly targets binocular function and has been found to improve both monocular and binocular vision in adults and children with amblyopia. Furthermore, non-invasive brain stimulation techniques that alter excitation and inhibition within the visual cortex have been shown to improve vision in the amblyopic eye. The aim of this review is to summarize this previous work and interpret the therapeutic effects of binocular therapy and non-invasive brain stimulation in the context of three potential neural mechanisms; active inhibition of signals from the amblyopic eye, attenuation of information from the amblyopic eye and metaplasticity of synaptic long term potentiation and long term depression.

Visual acuity improvement in adult amblyopic eyes with an iris-fixated phakic intraocular lens: Long-term results

To evaluate the effect of implantation of iris-fixated phakic intraocular lenses (pIOLs) (Artisan) in adult amblyopic eyes. Optical Express, London, United Kingdom. Retrospective case series. The study analyzed data from 5 years of follow-up of amblyopic eyes that were implanted with iris-fixated pIOLs and had a preoperative corrected distance visual acuity (CDVA) of 6/15 or worse. Visual acuity, refraction, endothelial cell count, and complications were assessed. Data for 103 eyes were analyzed as 2 groups. Group 1 comprised 82 eyes with myopia or myopic astigmatism, and Group 2 contained 21 eyes with hyperopia or hyperopic astigmatism. The mean preoperative sphere in Group 1 was -13.42 diopters (D) ± 5.62 (SD) with a mean cylinder of -2.35 ± 1.75 D. In Group 2, the mean sphere and cylinder were +6.77 ± 1.91 D and -2.63 ± 2.43 D, respectively. The mean CDVA improved from 0.51 ± 0.15 logMAR to 0.34 ± 0.16 logMAR (P<.001) in Group 1 and from 0.54 ± 0.17 logMAR to 0.46 ± 0.14 logMAR in Group 2 (P<.005). The safety index was 1.48 in Group 1 and 1.19 in Group 2. The efficacy index was 1.21 in Group 1 and 1.00 in Group 2. The mean gain in CDVA was statistically significantly greater in Group 1 (0.17 ± 0.14 logMAR) than in Group 2 (0.08 ± 0.11 logMAR). Two or more lines of CDVA were gained by 48.8% of eyes in Group 1 and by 19.0% of eyes in Group2. The iris-fixated pIOL was a safe and effective option for improving visual acuity in adult amblyopic eyes. Dr. Schallhorn is a consultant to Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Characteristics of fixational eye movements in amblyopia: Limitations on fixation stability and acuity?

Persons with amblyopia, especially those with strabismus, are known to exhibit abnormal fixational eye movements. In this paper, we compared six characteristics of fixational eye movements among normal control eyes (n=16), the non-amblyopic fellow eyes and the amblyopic eyes of anisometropic (n=14) and strabismic amblyopes (n=14). These characteristics include the frequency, magnitude of landing errors, amplitude and speed of microsaccades, and the amplitude and speed of slow drifts. Fixational eye movements were recorded using retinal imaging while observers monocularly fixated a 1° cross. Eye position data were recovered using a cross-correlation procedure. We found that in general, the characteristics of fixational eye movements are not significantly different between the fellow eyes of amblyopes and controls, and that the strabismic amblyopic eyes are always different from the other groups. Next, we determined the primary factors that limit fixation stability and visual acuity in amblyopic eyes by examining the relative importance of the different oculomotor characteristics, adding acuity (for fixation stability) or fixation stability (for acuity), and the type of amblyopia, as predictive factors in a multiple linear regression model. We show for the first time that the error magnitude of microsaccades, acuity, amplitude and frequency of microsaccades are primary factors limiting fixation stability; while the error magnitude, fixation stability, amplitude of drifts and amplitude of microsaccades are the primary factors limiting acuity. A mediation analysis showed that the effects of error magnitude and amplitude of microsaccades on acuity could be explained, at least in part, by their effects on fixation stability.

Comparison of Results after Daily Patching and Alternate-Day Patching to Treat Amblyopia

Purpose: We compared the results of daily patching and alternate-day patching to treat amblyopia. Methods: Patients with difference in the visual acuity (VA) between the eyes of at least two lines were prescribed spectacles according to the result of cycloplegic refraction. After 4 months, 45 patients with confirmed amblyopia were randomly assigned to daily patching or alternate-day patching group. Patients were patched daily in the daily patching group (n = 24), and patched every other day in another group. The patching time was 2-6 hours according to the VA of the amblyopic eye. The parents were asked to mark on a calendar whether their child performed occlusion or not. The main outcome measure was the mean VA of amblyopic eye and compliance of occlusion after 1, 3, 6 and 9 months. The success of treatment was defined if difference of VA between the eyes was less than or equal to 1 line. Results: There was no significant difference between the two groups in age, type of amblyopia, VA of the amblyopic eye and total treatment duration. VA of the amblyopic eye was significantly improved at 1 month after occlusion in both groups. At the final visit in both groups, the number of improved VA lines in the amblyopic eye (3.8 lines:3.7 lines, p = 0.754), the final success rate (50.0%:81.0%, p = 0.060) and the compliance of occlusion (94.5%:96.3%, p = 0.803) were not different significantly, but VA of the amblyopic eye (0.2 log MAR:0.1 log MAR, p = 0.042) was better in the alternate-day patching group than that in another group. Conclusions: There was no difference in the number of improved VA lines in the amblyopic eye, nor were there differences in success rate and compliance of occlusion between the two groups. The final VA was better in the alternate-day patching group than another group. Therefore, the alternate-day patching method is another possible option for the treatment of amblyopia. J Korean Ophthalmol Soc 2015;56(2):254-262

Comparison of Improvement Rates between Distance and Near Visual Acuity in Children with Unilateral Amblyopia

Purpose: To compare the improvement rates of distance visual acuity (VA) with that of near VA in amblyopic eyes of children with unilateral amblyopia. Methods: The medical records of children with unilateral amblyopia successfully treated with patching were reviewed. During subsequent visits for amblyopia treatment, subjects had best-corrected VA measured at 4 meters and 1/3 meters every 2 months. Duration of treatment to achieve equal VA between both eyes and improvement rates were compared between distance and near, and analyzed according to the cause and severity of amblyopia, or age. Results: A total of 76 children with amblyopia due to anisometropia and/or strabismus started amblyopia treatment at a mean age of 5.8 years and were followed up during a mean period of 16.4 months. Baseline VA was better at near than at distance in 52 children (68.4%), and better at distance than at near in 4 (5.3%). The mean duration of treatment was 5.4 months at distance and 3.9 months at near. However, the improvement rate considering the amount of improvement of VA was faster at distance; 0.11 log MAR/month at distance, and 0.08 log MAR/month at near (p = 0.016). The improvement rate differences between distance and near did not differ based on the cause of amblyopia, or age, whereas in mild amblyopia the improvement rate of distance VA was significantly faster than near. Additionally, children with better initial near VA tended to have a faster improvement rate of distance VA. Conclusions: Although baseline VA was better at near than at distance in more patients, the improvement rate was faster at distance than at near. Children with better initial near VA appeared to have a faster improvement rate of distance VA. J Korean Ophthalmol Soc 2015;56(9):1432-1438

P100 Wave Latency in Anisometropic and Esotropic Amblyopia versus Normal Eyes.

Purpose:To evaluate cortical activity using pattern visual evoked potentials (PVEPs) in patients with mild and moderate amblyopia (esotropic and anisometropic).Methods:PVEP was recorded in 43 unilateral amblyopic patients, including 15 esotropic (ET) and 28 anisometropic (AM) patients, selected from three different medical centers in the city of Shiraz, Iran and compared to that obtained from 15 age and sex matched normal subjects who served as controls. Visual acuity (VA) in amblyopic eyes was equal to or less than 0.7 LogMAR. The latency of P100 was recorded monocularly using two check sizes of 15 and 60 min of arcs at two different levels of contrasts (30% and 100%).Results:P100 latency in amblyopic eyes was significantly increased compared to the normal group (P < 0.001). There was a significant difference (P < 0.001) in P100 latency in anisometropic and esotropic amblyopic eyes as compared to normal subjects, using high spatial frequency and with both levels of contrast. A significant difference was observed with large check sizes and high contrast between anisometropic amblyopic and normal eyes (P = 0.03). However, there was no significant difference between these two groups and the control group with other stimuli.Conclusion:The neural response based on p100 latency in PVEP was different between amblyopic groups and normal subjects. PVEP may be valuable for diagnosis, prognosis and treatment of amblyopia.

Development and evaluation of a patching treatment questionnaire for Chinese amblyopic children

Background Amblyopia is a common disease for children. The main treatment approach for amblyopia is to patch the normally sighted eye and force the use of the amblyopic eye. However, patching treatment in children may negatively impact psychological well-being of both the child and family. At present, no specific questionnaire is available to assess the health-related quality of life (HRQoL) of amblyopic treatment for children and their families in China. The purpose of our study was to develop a Chinese version of patching treatment questionnaire, and evaluate its reliability and validity. Methods The original patching treatment questionnaire of amblyopia treatment index (ATI) was translated into Chinese. Amblyopic patients aged 4–9 years receiving patching 4–8 hours per day or full-time were recruited. The reliability and validity of the Chinese version of the patching treatment questionnaire were determined by internal consistency, test-retest reliability, item-scale correlations, and construct validity. The associated baseline factors and the questionnaire responses were assessed. Results One hundred and nine children with amblyopia treated with patching were enrolled. Distribution of response options for individual items and correlation with the respective subscale were calculated. Factor analysis revealed that 16 of the 21 items were loaded in the three subscales as follows: “adverse effects” of treatment, “difficulties with compliance” and “‘social stigma” of treatment. Internal consistency values measured by Cronbach's α coefficient (0.768) and split-half coefficient (0.790) were satisfactory for the total scales. The intra-class correlation coefficient for test-retest reliability was 0.998. No significant difference was found between the overall questionnaire scores and children's age, sex, baseline visual acuity of amblyopic eyes, improvement of the amblyopic eye, or patching time. Conclusions We developed a Chinese version of the patching treatment questionnaire with satisfactory reliability and validity. Validation in a patch-treated pediatric amblyopic population indicated that the questionnaire may be useful for Chinese children.

Outcome of conventional treatment for adult amblyopia

To ascertain whether conventional treatment can improve visual function in adults with amblyopia. Sixteen patients aged 21-67 years old were instructed to wear glasses for refractive correction and to patch the non-amblyopic eye for at least 1 h per day. Visual acuity, measured with crowded optotypes for distance and near acuity, was checked every 3 months, and followed for a mean (SD) of 14.1 (4.2) months. Prognostic factors related to the subsequent results, an improvement of 3 or more lines logMAR in distance visual acuity, were evaluated. Of 16 patients, 5 (31 %) improved 3 or more lines of distance and 5 (31 %) in near acuity. The mean improvement in distance was 2.4 lines logMAR (95 % CI 1.4-3.5) and 2.4 lines logMAR for near acuity (95 % CI 1.5-3.3). Patients aged under 45 years (p = 0.0357) and with severe amblyopia (p = 0.0337), defined as a corrected distance visual acuity of worse than -0.699 logMAR, were associated with a good response. Conventional treatment may improve the visual acuity of amblyopic eyes even in adult patients.

A Randomized Trial of Increasing Patching for Amblyopia

After treatment with refractive correction and patching, some patients have residual amblyopia resulting from strabismus or anisometropia. We conducted a clinical trial to evaluate the effectiveness of increasing prescribed daily patching from 2 to 6 hours in children with stable residual amblyopia. Prospective, randomized, multicenter clinical trial. A total of 169 children aged 3 to <8 years (mean, 5.9 years) with stable residual amblyopia (20/32-20/160) after 2 hours of daily patching for at least 12 weeks. Random assignment to continue 2 hours of daily patching or increase patching time to an average of 6 hours/day. Best-corrected visual acuity (VA) in the amblyopic eye after 10 weeks. Baseline VA was 0.44 logarithm of the minimum angle of resolution (logMAR) (20/50(-2)). Ten weeks after randomization, amblyopic eye VA had improved an average of 1.2 lines in the 6-hour group and 0.5 line in the 2-hour group (difference in mean VA adjusted for acuity at randomization = 0.6 line; 95% confidence interval, 0.3-1.0; P = 0.002). Improvement of 2 or more lines occurred in 40% of participants patched for 6 hours versus 18% of those who continued to patch for 2 hours (P = 0.003). When amblyopic eye VA stops improving with 2 hours of daily patching, increasing the daily patching dosage to 6 hours results in more improvement in VA after 10 weeks compared with continuing 2 hours daily.