Anisometropic Amblyopia Research Articles

Deficits in Reach Planning and On-Line Grasp Control in Adults With Amblyopia.

Adults with amblyopia exhibit impairments when reaching to grasp three-dimensional objects. We examined whether their deficits derive from problems with feedforward planning of these prehension movements or in using visual feedback to control them on-line. Twenty-one adults with mild to severe anisometropic and/or strabismic amblyopia and reduced binocularity participated, along with 21 normally sighted age- and gender-matched controls. Subjects used their preferred hand to reach for, precision grasp, and then lift cylindrical table-top objects (two sizes, two distances) using binocular, dominant eye, or amblyopic/non-sighting eye vision just to plan their movements during a 1-second task preview with vision then occluded so feedback was absent or to plan and execute them (i.e., with visual feedback fully available). Kinematic and error measures of the timing and accuracy of the reach and grasp were quantified by view and feedback and compared by ANOVA. The amblyopic adults performed generally worse than controls across all three views in both feedback conditions. With vision for planning only, their movement initiation and duration times were significantly increased, as were their initial reach times and error rates, especially when using the amblyopic eye alone, whatever its visual acuity loss. These relative planning deficits were only partially rectified with visual feedback available on-line. Relative grasp planning deficits were less evident in the amblyopia group, who instead produced significantly increased grip times and errors under binocular and amblyopic eye visual feedback conditions, although the subgroup with unmeasurable stereovision also formed wider (inaccurate) grasps across all conditions. Adults with amblyopia seem to have problems constructing reliable internal spatial representations for the feedforward planning of prehension, particularly with their affected eye and mainly affecting their reach, with additional deficits in on-line grasp control related to poor binocularity.

Evaluation of the Effect of Inferior Oblique Myectomy on Corneal and Anterior Segment Parameters

Purpose: This study aimed to evaluate the effect of inferior oblique myectomy (IOM) surgery on the cornea and anterior segment. Methods: The sheimpflug corneal topographies of 56 eyes of 33 patients who underwent IOM were analyzed at preoperative, postoperative 1 week, 1 month, 3 months, and 6 months. Astigmatism degree (Cyl), astigmatism axis (Ax), K1, central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), iridocorneal angle (ICA), and horizontal visible iris diameter (HVID) were evaluated. Results: The mean corneal Cyl, K1, ICA, ACD, and HVID did not change after IOM (p=0.671, p=0.377, p=0.431, p=0.588, p=0.795, respectively). There was a statistically significant change in Ax (p=0.025). The right Ax decreased, and the left Ax increased the most at 1 month (p=0.025, p=0.882, respectively). Ax increase was also detected in the left eye that was not operated on. The mean CCT increased and mean ACV decreased at 1 month (p=0.588, p=0.270, respectively), but these changes returned to preoperative values at 3 months. Conclusion: The manifestation of anterior segment alterations and intorsion in both eyes following inferior oblique myectomy may contribute to diminished visual acuity and the potential onset of amblyopia. These alterations merit consideration during the assessment, and if deemed necessary, the provision of new spectacles should be considered as a preventive measure against anisometropic amblyopia.

Factors affecting the total occlusion time in eyes with hyperopic anisometropic amblyopia

BackgroundAmblyopia treatment by occluding the healthy eye is known to be effective during a sensitive critical period. This study aims to clarify the factors for the total occlusion time (TOT) required for the amblyopic eye to achieve a normal visual acuity (VA) level of 1.0 (0.0 logMAR equivalent). This could contribute to an efficient treatment plan for eyes with hyperopic anisometropic amblyopia.MethodsSubjects were 58 patients (26 boys and 32 girls; age range, 3.6-9.2, average, 5.8 ± 1.3 years) with hyperopic anisometropic amblyopia. All the subjects had initially visited and completed occlusion therapy with improved VA of 1.0 or better in the amblyopic eye at Kindai University Hospital between January 2007 and March 2017. Using the subjects’ medical records, we retrospectively investigated five factors for the TOT: the age at treatment, the initial VA of the amblyopic eye, refraction of the amblyopic eye, anisometropic disparity, and the presence of microstrabismus. Patient’s VA improvement at one month after treatment was also evaluated to confirm the effect of the occlusion therapy.ResultsThe initial VA of the amblyopic eye ranged from 0.1 to 0.9 (median, 0.4). The TOT ranged from 140 to 1795 (median, 598) hours with an average daily occlusion time of 7 hours. The initial VA of the amblyopic eye and presence of microstrabismus were the significant factors for the TOT (p < 0.01). To achieve VA of 1.0 or better, patients with an initial VA of ≤ 0.3 in the amblyopic eye required a longer TOT. Moreover, patients with concomitant microstrabismus required a 1.7-fold longer TOT compared to those without microstrabismus.ConclusionLonger daily occlusion hours and early start of the treatment will be necessary for patients with poor initial VA or microstrabismus to complete occlusion therapy within the sensitive critical period.

Randomized Controlled Trial of Patching versus Dichoptic Stimulation Using Virtual Reality for Amblyopia Therapy

Purpose: To compare the outcomes of patching to dichoptic stimulation using virtual reality (VR) in moderate and severe amblyopia. Methods: This study was conducted on 86 subjects with unilateral anisometropic and mixed amblyopia. The subjects were randomized to the VR or patching group. The VR group received treatment using the Vivid Vision software (Vivid Vision Inc., San Francisco, USA) with each subject receiving weekly 2 h-sessions for 10 weeks. The patching group was prescribed patching for 10 weeks. Best-corrected visual acuity (BCVA) was measured using a single crowded letter in an ETDRS chart before, after 10 weeks of treatment, and after another 10 weeks of cessation of treatment. Near stereoacuity was measured using the TNO test. Results: Forty-two patients were randomized to the patching group and 44 to the VR group. The median age of the subjects was 12.0 (range 6.0 to 37.0) years. In the VR group, mean amblyopic eye BCVA showed statistically significant improvement by 0.89 line (95% confidence interval {CI}, 0.73 to 1.35 lines; p < 0.001) after 10 weeks of therapy, and after another 10 weeks of follow-up by 1.32 lines from baseline (95% CI, 1.15 to 1.7 lines; p < 0.001). Regarding the patching group, mean BCVA showed statistically significant improvement after 10 weeks by 1.38 lines (95% CI, 0.82 to 1.8 lines; p < 0.001), and after another 10 weeks by 1 line from baseline (95% CI, 0.06–0.147; 0.6 to 1.47 lines; p < 0.001). There was no significant difference between both groups at any time-point (p values >0.05). No serious adverse events were noted. Adults and severe amblyopes in the VR group showed more significant VA improvement than their counterparts in the patching group. Conclusions: Amblyopes treated using VR dichoptic treatment demonstrated statistically significant VA improvement after 10 and 20 weeks of follow-up that is comparable to patching.

Digital Therapy for Visual Acuity and Binocular Function in Children with Anisometropic Amblyopia.

Amblyopia affects development of children's monocular vision and binocular function and becomes a largely intractable problem with increasing aging. This study is to investigate the binocular function and evaluate efficacy of digital therapy in children 8-13 years of age with anisometropic amblyopia. The patients in the digital therapy group performed the training with the digital amblyopia therapeutic software. The visual acuity and binocular function (perceptual eye position [PEP], suppression, and stereopsis) were examined at the first visit and 3-month post-treatment. Twenty-three cases in the control group and 25 cases in the digital therapy group were enrolled. The results revealed that 3-month digital therapy can effectively improve corrected distance visual acuity (CDVA) and improve the binocular function, including PEP, suppression, and second-order stereopsis in children with anisometropic amblyopia, 8-13 years of age. Digital therapy for amblyopia can effectively improve monocular CDVA of amblyopic eyes and binocular function in older children with anisometropic amblyopia.

Visual parameter status as a predictive factor for the outcomes of occlusion therapy in anisometropic amblyopia.

The purpose is to compare visual parameters between normal and amblyopic eyes in anisometropic amblyopia and to find predictive factors for occlusion therapy. Sixty patients with anisometropic amblyopia between the ages of 5 and 25 years were enrolled in the prospective, longitudinal, and interventional study. Patients were selected based on no improvement with spectacle correction alone after 1 month of follow-up. Baseline parameters such as LogMAR visual acuity, LEA contrast sensitivity, TNO stereopsis test, online Farnsworth D-15 test for color vision, accommodation with RAF ruler, +2.00/-2.00 flipper test, and dynamic retinoscopy were recorded. All patients were treated with occlusion therapy depending on their grades of amblyopia. After 6 months of follow-up, improvement in visual acuity was recorded with a LogMAR chart and correlated with initial visual parameters. Paired "t" test, Chi-square test, independent "t" test, analysis of variance test were used as statistical analysis. Visual functions such as contrast sensitivity, accommodative facility, near point of accommodation, and accommodative amplitude showed a statistically significant difference between normal and amblyopic eyes of anisometropic amblyopia patients, whereas color vision did not differ significantly between normal and amblyopic eyes. Sixty-seven percentage of patients had poor stereopsis. Eighty percentage of patients who were younger had improvement in final best-corrected visual acuity and these patients had better stereopsis, contrast sensitivity, and mild-to-moderate amblyopia on initial testing. The age of the patient, degree of anisometropia, spherical equivalent in amblyopic eyes, stereopsis, contrast sensitivity values at initial presentation, and compliance to occlusion therapy were found to be positive predictive factors of occlusion therapy.

The Suppressive Basis of Ocular Dominance Changes Induced by Short-Term Monocular Deprivation in Normal and Amblyopic Adults.

We aimed to study the effect of short-term monocular deprivation on the suppressive interocular interactions in normals and amblyopes by using a dichoptic masking paradigm. Nine adults with anisometropic or mixed amblyopia and 10 control adults participated in our study. The contrast sensitivity in discriminating a target Gabor dichoptically masked was measured before and after 2 hours of monocular deprivation. The mask consisted of bandpass-filtered noise. Both the target and the mask were horizontally oriented at the spatial frequency of 1.31 cpd. Deprivation was achieved using an opaque patch on the amblyopic eye of amblyopes and the dominant eye of controls. Results were similar in both controls and amblyopes. After 2 hours of monocular deprivation, the previously patched eye showed a significant increase in contrast sensitivity under dichoptic masking, which also suggested reduced suppressive effect from the nonpatched eye. Meanwhile, the contrast sensitivity of the nonpatched eye remained almost unchanged under dichoptic masking. We demonstrate that the ocular dominance changes induced by short-term monocular deprivation-namely, the strengthening of the deprived eye's contribution-are associated with the unilateral and asymmetric changes in suppressive interaction. The suppression from the nondeprived eye is reduced after short-term monocular deprivation. This provides a better understanding of how inverse patching (patching of the amblyopic eye) could, by reducing the suppressive drive from the normally sighted (nondeprived) eye, form the basis of a new treatment for the binocular deficit in amblyopia.

Is there value in measuring near visual acuity during occlusion therapy for amblyopia?

ABSTRACT Introduction: The purpose of this study was to investigate near and distance visual acuity (VA) prior to, during and on completion of occlusion therapy for amblyopia. Method: Fifty-four patients aged 4–7 years (mean 4.9; ±0.44) with untreated strabismic, anisometropic or mixed amblyopia were recruited to the study following refractive adaptation where applicable. All patients underwent conventional occlusion (patching). Uniocular near and distance VA was tested using age and ability appropriate Crowded LogMAR VA tests prior to, during and upon conclusion of occlusion therapy. Results: In amblyopic eyes, there was no significant difference between near and distance VA prior to occlusion therapy with LogMAR Crowded (p = .66; mean distance VA at 3 m = 0.6 LogMAR; mean near VA at 40 cm = 0.58 LogMAR), or with LogMAR Crowded Kay Picture test (p = .78, mean distance VA at 3 m = 0.44 LogMAR; mean near VA at 33 cm = 0.46 LogMAR;). No significant difference was found between near and distance VA at any visit during occlusion therapy, or on completion of occlusion therapy with LogMAR Crowded (p = .86, mean final distance VA at 3 m = 0.266 LogMAR; mean final near VA at 40 cm = 0.25 LogMAR) or LogMAR Crowded Kay Pictures (p = .74, mean final distance VA at 3 m = 0.16 LogMAR; mean final near VA at 33 cm = 0.16 LogMAR). There was no significant difference in the VA of the fellow (non-amblyopic) eyes prior to and on completion of occlusion therapy with LogMAR Crowded at distance (3 m) or near (40 cm) (p = .05, p = .40 respectively); or with LogMAR Crowded Kay Pictures at distance (3 m) or near (33 cm) (p = .89, p = .35 respectively). Discussion: Improvement in VA of amblyopic eyes did not significantly differ between near and distance testing proximites at any point during the course of occlusion therapy for amblyopia in our study. These findings may aid clinicians with appropriate test selection and help with clinical time pressures. Where patient concentration does not allow for uniocular distance vision, uniocular near vision may be used to diagnose amblyopia, and vice versa. This could prevent delay in the treatment of amblyopia.

Case report of uniocular diplopia in a 26-year-old female: A diagnostic dilemma

A 26-year-old female had complaints of left eye monocular diplopia, blurred, wavy vision for 4 months and was diagnosed and managed as Dry eye syndrome outside. She did not improve clinically and presented to us. Routine ophthalmologic evaluations, including keratometry, slit lamp biomicroscopy, and fundoscopy, were done to rule out anterior and posterior segment etiologies. MRI brain and visual fields were done to rule out neurological causes. Provisional diagnosis of unilateral anisometropic amblyopia was made. On LASIK evaluation, she was found to have keratoconus suspect in corneal topography, and diagnosis of posterior keratoconus was confirmed with higher diagnostic tests like optical coherence tomography anterior segment and corneal tomography. She was managed with Cretan plus protocol. One must have a higher index of suspicion toward corneal ectatic disorders in this particular type of symptomatology of young patients.

Factors affecting the benefit of glasses alone in treating childhood amblyopia: an analysis of PEDIG data

BackgroundTo evaluate factors associated with better outcomes from optical treatment alone in amblyopic children from 3 up to 7 years.MethodsData extracted from two studies with similar protocols, Amblyopic Treatment Studies 5 (n = 152) and 13 (n = 128) from the Pediatric Eye Disease Investigator Group database, were used to determine by regression analysis the factors associated with improvements in visual acuity in the amblyopic eye, inter-ocular visual acuity difference and stereoacuity. Input variables were aetiology of amblyopia (anisometropic, strabismic and combined-mechanism amblyopia), treatment compliance, visual acuity, interocular visual acuity difference, stereoacuity, tropia size at distance and near, age and refractive error at baseline.ResultsDespite the range of clinical factors considered, our models explain only a modest proportion of the variance in optical treatment outcomes. The better predictors of the degree of optical treatment success in amblyopic children are visual acuity of the amblyopic eye, interocular visual acuity difference, stereoacuity, treatment compliance and the amblyopic eye spherical-equivalent refractive error. While the aetiology of the amblyopia does not exert a major influence upon treatment outcome, combined-mechanism amblyopes experience the smallest improvement in visual acuity, tropia and stereoacuity and may need longer optical treatment periods.ConclusionsWhile results identify the factors influencing optical treatment outcome in amblyopic children, clinicians will be unable to predict accurately the benefits of optical treatment in individual patients. Whether this is because relevant clinical or non-clinical factors (e.g. nature and volume of daily activities undertaken) influences the outcomes from optical treatment has not yet been identified and remains to be discovered.

Amblyopia treatment outcomes in patients with neurodevelopmental disorders

To compare amblyopia treatment outcomes between patients with neurodevelopmental disorders and their typically developing peers. Of 2,311 patients diagnosed with amblyopia between 2010 and 2014 at Boston Children's Hospital, 460 met inclusion criteria (age 2-12 with anisometropic, strabismic, or mixed amblyopia [interocular difference (IOD) ≥2 lines]). Treatment and visual outcomes were analyzed according to neurodevelopmental status: neurodevelopmental delay (DD) versus typical development (TD). The DD group (n = 54) and TD group (n = 406) were similar in demographics, amblyogenic risk factors, baseline visual measures, prescribed therapy, and adherence (P ≥ 0.10). Between-visit follow-up time was longer for the DD group (0.65 [0.42- 0.97] years) than for the TD group (0.5 [0.36-0.82] years; P = 0.023). IOD improved similarly in each group by the last visit (DD, -0.15 logMAR [-0.31 to -0.02]; TD, -0.2 logMAR [-0.38 to -0.1]; P= 0.09). Each group reached amblyopia resolution by the last visit at similar frequencies (DD, 23/54 [43%]; TD, 211/406 [52%]; P > 0.2). DD diagnosis did not independently influence amblyopia resolution (HR, 0.77; 95% CI, 0.53-1.12; P = 0.17), but each additional month of interval time between follow-up visits reduced the likelihood of resolution by 2.7% (HR, 0.67; 95% CI, 0.51-0.87; P = 0.003). Patients with DD and those with TD responded similarly to amblyopia therapy; however, follow-up intervals were longer in patients with DD and correlated with the likelihood of persistent amblyopia, suggesting that greater efforts at assuring follow-up may benefit patients with DD.

Choroid vascular changes in hyperopic anisometropia amblyopia using SS-OCTA

PurposeTo observe and understand the structural changes in choroidal vessels in eyes with hyperopic anisometropic amblyopia using swept-source optical coherence tomography angiography (SS-OCTA).MethodsA total of 44 patients were enrolled in this study: 22 children with hyperopic anisometropic amblyopia and 22 age-matched controls. SS-OCTA was used to scan the 6*6 mm macular area of their eyes. The average choroidal thickness (CT) and choroidal capillary flow area (CC) in a 3 mm diameter area centered on the macular area were obtained. The choroidal vascularity volume (CVV) was automatically extracted and 3D reconstructed by inbuild software, and the three-dimensional choroidal vascularity index (3D-CVI) was calculated. The effect of amblyopia on the choroidal vessel structure was assessed using generalized linear estimating equations (GEEs) corrected for axial length, sex, age, and best-corrected visual acuity.ResultsThe CC was greater in amblyopic eyes than in fellow eyes (P = 0.014) but was not significantly different from that in control eyes (P = 0.963). After correcting for sex, age, axial length, and visual acuity using GEEs, the mean CT in the amblyopic eyes was greater than that in the fellow eyes (P = 0.030) but was not significantly different from that in the control eyes (P = 0.160). The 3D-CVI in amblyopic eyes was higher than that in control eyes (P = 0.038) but was not significantly different from that in fellow eyes (P = 0.407). The three-dimensional choroidal vascularity volume (3D-CVV) was higher in amblyopic eyes than in fellow eyes (P = 0.046) and control eyes (P = 0.023).ConclusionsWe found that eyes with hyperopic anisometropic amblyopia demonstrated higher CT, CC and 3D-CVV values than the contralateral eyes after correction, while the 3D-CVI was unchanged. Compared with control eyes, amblyopic eyes had higher 3D-CVV and 3D-CVI values but similar CT and CC values. Amblyopic eyes may have different choroidal vascular structures from fellow and control eyes.

OCT-Angiography Findings in Children with Anisometropic Amblyopia.

The purpose of this prospective study is to show findings of OCT angiography in children with anisometropic amblyopia with a statistically significant difference, regardless of the type of refractive disorder, between the amblyopic and the fellow eye. This research aimed to establish whether there is a difference in vascular density [VD] and size of the foveal avascular zone [FAZ] in the superficial capillary plexus [SCP]. All children between 9 and 18 years of age who were treated at the Outpatient Clinic for Orthoptics and Pleoptics of the Department of Ophthalmology, University Medical Centre Maribor from January 2020 to December 2022 due to unilateral anisometric amblyopia were enrolled in our study. Fourteen children met the criteria. Cirrus 5000 high-resolution OCT with AngioPlex OCT angiography was used to analyze the size of the FAZ and VD in the SCP and TCS. The paired t-test or Wilcox signed-rank test [p < 0.05] was used for statistical analysis of each parameter between the amblyopic and fellow eye. Mean child age was 13 years ± 2.9 and ranged from 9 to 18 years. Most of the children [85.7%] were boys. The VD of the SCP did not show statistically significant differences between the visually impaired and control eyes [p = 0.328]. The comparison of the FAZ area between the two eyes was also not statistically significant [p < 0.808]. There was also no statistically significant difference in central macular thickness [TCS] [p < 0.291]. Our research results show no statistically significant differences in the VD and the FAZ of the SCP, and in the TCS between the amblyopic and fellow eye in children with unilateral anisometropic amblyopia. Our research did not confirm the results of certain previous studies in which a lower density of the capillary network was present in the visually impaired eye. Further studies with more children are necessary to confirm our results.

Pattern visual evoked potential and foveal sensitivity in amblyopia.

Amblyopic eyes show impaired visual functions such as poor visual acuity and reduced foveal sensitivity. The purpose of this study was to determine the association between foveal threshold and visual evoked potentials (VEP) in strabismic and anisometropic amblyopia. Forty-five subjects (age range: 7-28years, 43.3% female) including 15 strabismic and 15 anisometropic amblyopes, and 15 age-similar control subjectsparticipated in this study. Each subject had pattern visual evoked potentialsand foveal threshold recorded in each eye using RetiScan (Roland Consult, Germany) and Humphrey Visual Field Analyzer II (HFA II; Carl Zeiss Meditec Inc., Dublin, CA), respectively. These outcomes were comparedamong the amblyopic eyes, their fellow eyes, and the control eyes. Compared to the amblyopic eyes (Mean ± SD: 33.4 ± 3.48dB), the foveal threshold was higher in fellow eyes (37.0 ± 2.04dB, p = 0.0002) and incontrol eyes (38.7 ± 0.96dB, p < 0.0001). Strabismic amblyopes had a lower foveal threshold than anisometropic amblyopes (31.8 ± 3.86 vs. 35.0 ± 2.17dB, p = 0.005). Relative to the P100 peak time in fellow eyes (1°checks:116.1 ± 9.00ms; 0.25°checks:118.8 ± 5.67ms), amblyopic eyes had delayed P100 peak times for both 1° (122.7 ± 11.4ms, p < 0.0001) and 0.25° (130.4 ± 11.2ms, p < 0.0001) check sizes. There were also significant differences in P100 peak time between amblyopic and control eyes (1°:122.7 ± 11.4 vs.112.4 ± 5.01ms, p = 0.15; 0.25°:130.4 ± 11.2 vs.113.9 ± 5.71ms, p < 0.0001) and between fellow and control eyes (0.25°:118.8 ± 5.67 vs.113.9 ± 5.71ms, p = 0.009). Amblyopic eyes exhibited lower N75-P100 amplitudes than fellow eyes (1°:12.6 ± 7.96 vs.15.9 ± 8.82µV, p = 0.01; 0.25°:10.6 ± 6.11 vs. 15.8 ± 10.6µV, p = 0.001) and control eyes (0.25°: p = 0.0008). Foveal threshold correlated negatively with P100 peak time (1°: r = -0.45, p = 0.002 and 0.25°: r = -0.58, p < 0.0001) and positively with N75-P100 amplitude responses (1°: r = 0.42, p = 0.004 and 0.25°: r = 0.52, p = 0.002). Amblyopic eyes showed reduced pattern VEP amplitudes and delayed peak times with significant associations with the foveal sensitivity. However, the VEP measures overlapped extensively between amblyopic and control eyes with no apparent criterion value for optimal discrimination, suggesting that foveal sensitivity might be a better discriminator of amblyopia than pattern VEP.

Correlation between Visual Acuity, Contrast Sensitivity and Depth of Vision before and after Partial Time Occlusion Therapy in Strabismic and Anisometropic Amblyopes

Background Amblyopia is known as the visual developmental disorder that follows selective disruption of the visual input to one eye early in life. It is considered the second most common cause of decreased visual acuity in both children and adults affecting greatly both economic and social life. It affects most of the visual parameters, so great efforts are carried out in developing effective methods controlling different deficits in amblyopia, being a great concern for all the society. However, monocular occlusion therapy remains the easiest and most popular way despite that there are many doubts in its reliability in controlling visual abnormalities other than acuity. Purpose To compare the different performance of anisometropic and strabismic eyes with moderate amblyopia, using partial occlusion therapy regarding visual acuity, contrast sensitivity and depth of vision. Methods Forty-nine children between 7 and 12 years old suffering from moderate amblyopia were classified into two groups: 25 anisometropic amblyopes and 24 strabismic ones. Two hour occlusion regimen with near activity was conducted by patients, assured by parents monitoring. Evaluation of visual acuity, contrast sensitivity and stereoacuity was conducted at each visit throughout the treatment regimen which was continued for 6 months on monthly follow up basis. Results Children in both groups improved significantly in visual acuity. There was a considerable difference among the distribution of improvement within each group where 9% of strabismic amblyopes achieved full visual recovery as compared to 40% in the anisometropic group, and 62.5% had residual amblyopia as compared to 36% in the anisometropic one, in spite of no significant difference of average improvement between groups (&amp;lt;0.0001). Only 42% of the strabismic amblyopes improved in stereoacuity as compared to 88% of the anisometropic ones, however, the difference in mean improvement was not significant between the two groups. Conclusion Children with moderate anisometropic or strabismic amblyopia 7-12 years old, can get considerable benefits from part time occlusion therapy in different visual aspects. The anisometropic amblyopes have better contrast sensitivity improvement and more reliable expectations of recovery being largely dependent on the initial visual acuity.

Relationship Between Suppression Scotomas and Stereoacuity in Anisometropic Amblyopia With Successfully Treated Visual Acuity.

The purpose of this study was to investigate the relationship among suppression scotoma size, stereoacuity, and four-prism base-out test (4ΔBOT) results in anisometropic amblyopia with successfully treated visual acuity. We included 103 cases of anisometropic amblyopia successfully treated for visual acuity without strabismus. Stereoacuity was measured using a Randot Stereotest. The size of the suppression scotomas was measured using a new device, the polarized four dot (P4D) test. This is a modification of the Worth 4 dot test (W4D) device. The patients were divided into three groups based on the 4ΔBOT results: normal (group A = 29 cases), subnormal (group B = 48 cases), and abnormal (group C = 26 cases) response groups. The horizontal diameter of the suppression scotomas and stereoacuity in logarithmic values with a base of 20 seconds of arc (″) were compared among the 3 groups. The mean age at P4D testing was 8.4 ± 2.1 years. The average horizontal diameters of the suppression scotomas were 0.35 ± 0.79Δ, 2.01 ± 0.82Δ, and 5.50 ± 2.72Δ in groups A, B, and C, respectively, showing significant differences (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). The average logarithmic stereoacuity were 1.07 (24.95″), 1.22 (38.84″), and 1.47 (82.79″) in groups A, B, and C, respectively, thereby showing significant differences between the groups (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). Stereoacuity and horizontal diameter of the suppression scotoma were strongly correlated (r = 0.732, P < 0.0001). The suppression scotoma size measured using P4D correlated significantly with stereoacuity and the 4ΔBOT results.

Macular superficial vascular density on optical coherence tomography angiography in children with unilateral anisometropic and bilateral hyperopic amblyopia

We analyzed whether macular superficial vascular density (SVD) and foveal vascular zone (FAZ) on optical coherence tomography angiography (OCTA) can distinguish between bilateral ametropic and anisometropic amblyopia. We included 42, 33, and 50 eyes in the bilateral ametropic amblyopia, anisometropic amblyopia, and normal control groups, respectively. Using macular swept-source optical coherence tomography angiography, we measured and analyzed the superficial FAZ areas and five sectoral macular SVDs after magnification correction. The anisometropic amblyopic eye group showed significantly increased foveal SVDs (p < 0.001) and significantly decreased superficial FAZ areas (p < 0.001), compared with the remaining groups. Additionally, the bilateral ametropic amblyopia group had significantly decreased nasal SVDs. SVDs and superficial FAZ areas differed among hyperopic amblyopia subtypes. These findings may reflect vascular distribution differences and macular changes in hyperopic amblyopia subtypes compared with normal eyes.

Treatment of Anisometropic Amblyopia with a Dichoptic Digital Platform in Argentinian Children and Adults

ABSTRACT Purpose To evaluate and compare the results of dichoptic training in Argentinian children and adults with anisometropic amblyopia. Methods Prospective non-comparative study enrolling 41 subjects with anisometropic amblyopia (age, 6–60 years old). Two groups were differentiated according to age, children (6–16 years, 24 subjects) and adults (>17 years, 17 subjects). All patients were treated with the Bynocs® platform (Kanohi Eye Pvt. Ltd, India) following a protocol of 30 sessions of training of 30 min daily 5 times a week for 6 weeks. Changes in corrected distance visual acuity (CDVA) and binocular function (BF) score with treatment were analyzed. Results In the whole sample, CDVA in the amblyopic eye improved significantly, with a mean change of 0.30 logMAR (p < .001). Likewise, a significant improvement was also found in BF score (p < .001), with a mean change of 1.14 log units. The change achieved in CDVA was significantly correlated with the baseline CDVA in the amblyopic eye (r=-0.568, p < .001). Furthermore, no significant differences were found between age groups in the change achieved in CDVA (p = .431) and BF with therapy (p = .760). Conclusions Dichoptic training with the digital platform evaluated provides an effective improvement of visual acuity and binocular function in children and adults with anisometropic amblyopia.

A pilot non-randomized trial of smartphone-based anaglyph system for treatment of adult amblyopia through VR (Virtual Reality).

To evaluate the effectiveness of amblyopia treatment through a smartphone-based anaglyph system by virtual reality (VR) in adult patients. A total of 10 subjects diagnosed with anisometropic amblyopia were enrolled during the study period. Best Corrected Visual Acuity (BCVA), stereoacuity, and contrast acuity were evaluated during three visits (at presentation, 3 months and 6 months) of smartphone-based anaglyph video run in the VR mode. All the amblyogenic factors including stereopsis, color vision, and contrast acuity were compared using Friedman two-way analysis of variance. Statistical significance was considered if P < 0.05. Mean BCVA in amblyopic eye improved significantly from a logMAR value of 0.73 ± 0.64 before Virtual reality vision therapy (VRVT) to a post-training VRVT value of 0.48 ± 0.44 (P < 0.01). Mean stereoacuity changed from a value of 560.00 ± 301.58 before VRVT to a value of 263.00 ± 143.58 seconds of arc after training (VRVT) (P < 0.01). Mean accommodation changes from a value of 15.00 ± 7.40 before training or VRVT to value of 12.60 ± 6.10 cm after training (P < 0.01). Mean contrast acuity changes from a value of 1.21 ± 0.72 at presentation to a value of 1.52 ± 0.49 log unit after VRVT. A smartphone-based anaglyph system using VR vision therapy appears to be an effective treatment option for amblyopia in adults.

Contour integration deficits at high spatial frequencies in children treated for anisometropic amblyopia.

This study was conducted to reexamine the question of whether children treated for anisometropic amblyopia have contour integration deficits. To do so, we used psychophysical methods that require global contour processing while minimizing the influence of low-level deficits: visibility, shape perception, and positional uncertainty. Thirteen children with anisometropic amblyopia (age: 10.1 ± 1.8 years) and thirteen visually normal children (age: 10.8 ± 2.0 years) participated in this study. The stimuli were closed figures made up of Gabor patches either in noise or on a blank field. The contrast thresholds to detect a circular contour on a blank field, as well as the thresholds of aspect ratio and contour element number to discriminate a circular or elliptical contour in noise, were measured at Gabor spatial frequencies of 1.5, 3, and 6 cpd for amblyopic eyes (AEs), fellow eyes (FEs), and normal control eyes. Visual acuities and contrast sensitivity functions for AEs and FEs and the Randot stereoacuity were measured before testing. The AEs showed contrast deficits and degraded shape perception compared to the FEs at higher spatial frequencies (6 cpd). When the influence of abnormal contrast sensitivity and shape perception were minimized, the AEs showed contour integration deficits at spatial frequencies 3 and 6 cpd. These deficits were not related to basic losses in contrast sensitivity and acuity, stereoacuity, and visual crowding. Besides, no significant difference was found between the fellow eyes of the amblyopic children and the normal control eyes in the performance of contour integration. After eliminating or compensating for the low-level deficits, children treated for anisometropic amblyopia still show contour integration deficits, primarily at higher spatial frequencies, which might reflect the deficits in global processing caused by amblyopia. Contour integration deficits are likely independent of spatial vision deficits. Refractive correction and/or occlusion therapies may not be sufficient to fully restore contour integration deficits, which indicates the need for the development of clinical treatments to recover these deficits.