Deficits of the "Good" Eye in Amblyopia: Processing Geometric Properties.

Purpose: Although fellow eyes of amblyopia are typically considered normal, recent studies have revealed impairments in certain aspects of vision. However, it remains unclear at which level of object processing these impairments occur. This study aims to investigate the functional level of visual perception impairment in the fellow eye of children and adults with amblyopia using the geometric functional hierarchy discrimination task based on Klein Mathematics methodology. Methods: Seventy-six patients with amblyopia (40 children and 36 adults) and 77 age-matched healthy controls (40 children and 37 adults) were recruited for this study. The participants completed four sets of geometric hierarchies (in ascending order of stability: Euclidean, affine, projective, and topology) and one set of color discrimination tasks. They were instructed to rapidly and accurately select a distinct shape from the four quadrants. Results: The participants' performance was evaluated using the inverse efficiency (IE) score (IE = response time (RT)/accuracy). The results of IEs show that the fellow eye of children with amblyopia exhibits normal topological processing, yet displays higher IEs in other geometric properties and color processing, suggesting impairments in these specific discrimination abilities. However, adults with amblyopia did not show deficits on any discrimination types compared with adult controls. Conclusions: The lack of compromised topological processing suggests that amblyopia may not have inflicted any damage to the subcortical visual pathways. Furthermore, these deficits observed in the fellow eye tend to diminish significantly during adulthood, implying that amblyopia may potentially hinder the maturation process of the fellow eye.

Analyses of eye movement parameters in children with anisometropic amblyopia.

OBJECTIVE: To investigate the characteristics of eye movement in children with anisometropic amblyopia, and to compare those characteristics with eye movement in a control group. METHODS: 31 children in the anisometropic amblyopia group (31 amblyopic eyes in group A, 31 contralateral eyes in group B) and 24 children in the control group (48 eyes in group C). Group A was subdivided into groups Aa (severe amblyopia) and Ab (mild-moderate amblyopia). The overall age range was 6-12 years (mean, 7.83 ± 1.79 years). All children underwent ophthalmic examinations; eye movement parameters including saccade latency and amplitude were evaluated using an Eyelink1000 eye tracker. Data Viewer and MATLAB software were used for data analysis. RESULTS: Mean and maximum saccade latencies, as well as mean and maximum saccade amplitudes, were significantly greater in group A than in groups B and C before and after treatment (P < 0.05). Mean and maximum saccade latencies were significantly different among groups Aa, Ab, and C (P < 0.05). Pupil trajectories in two detection modes suggested that binocular fixation was better than monocular fixation. CONCLUSIONS: Eye movement parameters significantly differed between contralateral normal eyes and control eyes. Clinical evaluation of children with anisometropic amblyopia should not focus only on static visual acuity, but also on the assessment of eye movement.

SPEctacle Correction for the TReatment of Amblyopia (SPECTRA): study protocol for a prospective non-randomised interventional trial in adults with anisometropic/mixed mechanism amblyopia.

INTRODUCTION: Amblyopia is a neurodevelopmental vision disorder typically affecting one eye, resulting in compromised binocular function. While evidence-based treatments exist for children, there are no widely accepted treatments for adults. This trial aims to assess the efficacy of appropriate optical treatment in improving vision and visual functions in adults with amblyopia. This is hypothesised to significantly improve visual acuity of the amblyopic eye and other visual functions. METHODS AND ANALYSIS: SPEctacle Correction for the TReatment of Amblyopia is a prospective non-randomised interventional trial. The following criteria for amblyopia will be used: best corrected visual acuity (BCVA) in the amblyopic eye of 0.3 to 1.0 (inclusive) logMAR VA and in the fellow eye, 0.1 logMAR or better, with an interocular VA difference of ≥2 logMAR lines. Eligible participants aged 18-39 will receive full/near-full optical treatment requiring wear for at least half their waking hours for the trial duration. A difference of ≥1.00D spherical equivalent between a participant's current refractive correction and the study prescription is required for eligibility. Primary outcome is the change in amblyopic eye BCVA from baseline to 24-week postenrolment. Secondary outcomes include distance and near VA of both eyes, stereoacuity, contrast sensitivity, interocular suppression, angle of strabismus and fixation stability measured at monthly intervals. Visual evoked potentials will also be measured at baseline, week 12 and week 24. Treatment compliance and quality of life for all participants will be monitored.Analyses comparing baseline and week 24 will utilise pairwise comparisons. Linear mixed models will be fitted to the data for measures taken monthly. This allows estimates and inferences to be drawn from the coefficients of the model, while handling missing data. ETHICS AND DISSEMINATION: Human ethics approval was obtained from the respective ethics board of the Hong Kong Polytechnic University (HSEARS20210915002) and the University of Waterloo (#44235). The study protocol will conform to the principles of the Declaration of Helsinki. Results will be disseminated through peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: NCT05394987; clinicaltrials.org.

Successful treatment of cortical visual impairment in children using anti-amblyopia treatment despite the absence of amblyopia: a case report.

BACKGROUND: Cortical visual impairment (CVI) is a verifiable visual dysfunction that cannot be attributed to disorders of the anterior visual pathways or any potentially co-occurring ocular impairment. Given the limited knowledge on the most effective interventions for visual impairment resulting from CVI, this case report provides valuable insights into an example of successful implementation of anti-amblyopia therapy in a patient with CVI. CASE PRESENTATION: This case report presents a 5-year-old girl with CVI secondary to hypoxic-ischemic injury, resulting in visual impairment, dyspraxia, and abnormal visual evoked potential testing. The girl did not suffer from amblyopia, there was no evidence of relevant refractive errors or strabismus, so visual pathway damage was the cause of her visual deficit. Nevertheless, the patient underwent anti-amblyopia therapy and showed significant improvement in visual acuity after 12 months of treatment. The improvement, resulting from visual stimulation, was due to a good functional recovery by a better usage of the damaged visual pathways. The therapy included prescribing corrective glasses and implementing secondary occlusion of the better eye for 4 months, which was protracted for another 4 months, leading to further improvements in visual acuity. CONCLUSIONS: The case report shows that addressing even minor refractive errors and implementing anti-amblyopia therapy can significantly improve vision in children with CVI, even without co-existing amblyopia. It also highlights the importance of early intervention and multidisciplinary rehabilitation in children with CVI, focusing on motor and cognitive skills. Additionally, it emphasizes the need for further research to establish evidence-based practice standards for improving vision in children with CVI.

Leukocoria in a 4-year-old boy.

A healthy 4-year-old boy referred for evaluation of an abnormal red reflex in the left eye was noted, on fundus examination, to have extensive white, striated lesions surrounding the optic nerve that involved the superior and inferior macular arcades. On further examination, he was found to have ipsilateral high myopia and amblyopia. The triad of unilateral myelinated retinal nerve fibers, myopia, and amblyopia led to a diagnosis of Straatsma syndrome, which requires early treatment to prevent permanent vision loss. Treatment comprised a contact lens for refractive correction of the left eye, patching of the right eye, and full-time polycarbonate protective lenses. With 2 years' follow-up, the left eye failed to improve appreciably.

Feasibility of a new 'balanced binocular viewing' treatment for unilateral amblyopia in children aged 3-8 years (BALANCE): results of a phase 2a randomised controlled feasibility trial.

OBJECTIVES: This study aimed to evaluate the safety of dichoptic balanced binocular viewing (BBV) for amblyopia in children, plus feasibility, adherence, acceptability, trial methodology and clinical measures of visual function. DESIGN: We carried out an observer-masked parallel-group phase 2a feasibility randomised controlled trial. SETTING: Two study sites, a secondary/tertiary and a community site. PARTICIPANTS: We enrolled 32 children aged 3-8 years with unilateral amblyopia who had completed optical adaptation where indicated. 20 children attended the 16-week exit visit (retention 63%). INTERVENTIONS: Children were randomised to BBV (movies customised to interocular acuity difference at baseline) for 1 hour a day (active intervention) or standard management as per parental choice (part-time occlusion or atropine blurring, control). All interventions were used at home, daily for 16 weeks. PRIMARY OUTCOME MEASURE: 'VacMan suppression test' of interocular balance at 16 weeks from randomisation. SECONDARY OUTCOME MEASURES: feasibility outcomes (recruitment and retention ratios, adherence with the allocated intervention); safety outcomes at other time points (changes in prevalence of diplopia, manifest strabismus, suppression/interocular balance on a range of tests); efficacy outcomes (clinical measures of visual function, such as best-corrected visual acuity, BCVA). Outcome measures were identical to those planned in the protocol. RESULTS: Primary outcome: At baseline, values for the interocular balance point were higher (indicating greater suppression of the amblyopic eye) in the occlusion group than in the BBV group. These values shifted downwards on average for the occlusion group, significantly decreasing from baseline to week 16 (t8=4.49, p=0.002). Balance values did not change between baseline and week 16 for the BBV group (t9=-0.82, p=0.435). At 16 weeks, there was no statistical difference in interocular balance/suppression change over time between the two arms. The difference at follow-up between the arms, adjusted for baseline, was -0.02 (95% CI -0.28 to 0.23, p=0.87). FEASIBILITY: We prescreened 144 records of potentially eligible children. Between 28 October 2019 and 31 July 2021, including an interruption due to the COVID-19 pandemic, 32 children were screened and randomised (recruitment rate 22%), 16 to BBV and 16 to standard treatment. 20 children attended the 16-week exit visit (retention 63%). Mean adherence with BBV as proportion of viewing time prescribed was 56.1% (SD36) at 8 and 57.9% (SD 30.2) at 16 weeks. Mean adherence with prescribed occlusion time was 90.1% (SD 19.7) at 8 and 59.2% (SD 24.8) at 16 weeks. SECONDARY SAFETY/EFFICACY OUTCOMES: One child in the BBV arm reported transient double vision, which resolved; two reported headaches, which led to withdrawal. BCVA improved from mean 0.47 (SD0.18) logMAR at randomisation to 0.26 (0.14) with standard treatment, and from 0.55 (0.28) to 0.32 (0.26) with BBV. Outcomes at 16 weeks did not differ between treatments. PARTICIPANT EXPERIENCE: Families were generally positive about BBV, but families found both patching and BBV difficult to integrate into family routines. CONCLUSIONS: Recruitment rates indicate that a future phase 3 trial will require multiple sites or a longer enrolment period. Retention and adherence rates were lower than anticipated, which will influence future study designs. Dichoptic treatment may be equal to occlusion treatment in safety and efficacy; headaches may lead to discontinuation. Integration into family routines may constitute a barrier to implementation. TRIAL REGISTRATION NUMBER: NCT03754153.

Combination of 2 test methods, single-picture optotype visual acuity chart and spot™ vision screener, in the eye health screening program for 3-year-old children in Tokyo: A retrospective, observational study.

To evaluate the usefulness of the Tokyo Metropolitan Government's Eye Health Screening Program for 3-year-old children, which combines the Single-Picture Optotype Visual Acuity Chart (SPVAC) and Spot™ Vision Screener (SVS) tests. This was a retrospective, observational, matched study. Patients who underwent the eye health screening program and had abnormalities were classified into 3 groups according to the outcomes of the SPVAC (SPVAC-passed, SPVAC-P; SPVAC-failed, SPVAC-F) and SVS (SVS-passed, SVS-P; SVS-failed, SVS-F) tests as follows: SPVAC-P/SVS-F, SPVAC-F/SVS-P, and SPVAC-F/SVS-F. We evaluated the age at examination, SPVAC and SVS test success rates, and SVS refractive power. Additionally, the rates of refractive error, amblyopia, and strabismus were compared among the 3 groups. The SPVAC-P/SVS-F, SPVAC-F/SVS-P, and SPVAC-F/SVS-F groups comprised 158, 28, and 74 eyes, respectively. The mean age was 37.4 months. The success rates of the SPVAC and SVS tests were 69.8% and 96.2%, respectively. The mean SVS hyperopia value in the SPVAC-F/SVS-F group (2.71 ±â€…1.50 D) was significantly higher than that of the SPVAC-P/SVS-F group. The mean SVS astigmatism and myopia values were -2.21 diopter (D) ±â€…1.09 D and -3.40 ±â€…1.82 D, respectively; they did not differ significantly from that of the SPVAC-P/SVS-F group. Significant differences were observed in the refractive error, amblyopia, and strabismus rates among the 3 groups. Regarding disease determination, no significant difference was observed among participants who passed and failed the SPVAC test, regardless of the outcome of the other test. However, a significant difference was observed between those passing and failing the SVS tests. The SPVAC method used to screen 3-year-old children should be modified to commence at 42 months of age or be replaced with a single Landolt C test. The SVS test is useful for screening younger patients. Furthermore, the SVS test showed that the degree of hyperopia was higher in patients who did not pass the SPVAC test.

[ECONOMIC INEQUALITY AND AMBLYOPIA TREATMENT SUCCESS RATES - EXPERIENCE OF A TERTIARY CENTER IN ISRAEL].

INTRODUCTION: Amblyopia is a common cause of visual impairment in children. There is circumstantial evidence for the correlation between living in impoverished areas and treatment failure. However, no large study directly assessed this correlation. AIMS: To check the correlation between socioeconomic status and amblyopia treatment success rates, in children 3-18 years old. METHODS: A retrospective cohort study, review of the electronic medical records of patients treated for amblyopia in a tertiary center during a period of 24 years. RESULTS: A total of 102 participants were enrolled in the study, of whom 50 came from impoverished areas and were the study group. The study and control group participants had similar distribution of age, sex and baseline clinical data. Study group participants had significantly lower baseline visual acuity. The mean follow-up time was 34 months. Both groups had a significant improvement in visual acuity and a significant decline in severe amblyopia proportion. Final visual acuity, visual improvement and amblyopia severity were similar in both groups. The proportion of successful treatments was similar in both groups. DISCUSSION: Although participants from impoverished areas began follow-up with significantly lower visual acuity, their vision has improved during follow-up and was similar to final visual acuity of the control group. Amblyopia treatment has eliminated the gap in visual acuity between amblyopic patients from impoverished areas and amblyopic patients in the general population. Conclusion: Given good treatment compliance, social disparities were not significant determinants of amblyopia treatment success.

[Cautious application of multifocal intraocular lenses in children with congenital cataracts].

Multifocal intraocular lenses (MIOLs) have demonstrated efficacy and safety in adult cataract surgery, yet they encounter many challenges in pediatric applications. This article elaborates on the difficulties in biometric measurements in children, the unpredictability of postoperative refraction outcomes, the lack of long-term spectacle independence in children with MIOLs, the absence of significant advantages in correcting childhood amblyopia, and the potential increase in the rate of secondary surgeries. Due to the insufficient clinical evidence supporting the use of MIOLs in children at present, it is proposed that MIOLs be cautiously applied to children with congenital cataracts in clinical practice. Further research in this area is encouraged.

Assessment of refractive errors, amblyopia, strabismus, and low vision among hearing-impaired and deaf students in Kermanshah.

BACKGROUND AND AIM: Refractive errors, amblyopia, strabismus, and low vision are more common among children with hearing impairments in comparison with their hearing peers. Neglecting visual disorders can pose educational and social problems for these children. The present study aimed to assess the prevalence of refractive errors, amblyopia, strabismus, and low vision among hearing-impaired and deaf students in Kermanshah. MATERIALS AND METHODS: A total of 79 deaf and hearing impaired students within the age range of 7-20 years (mean age of 15.01 ± 2.72) underwent optometric examinations, including autorefractometry, retinoscopy, ophthalmoscopy, slit lamp, visual acuity measurement, and cover-uncover test. Those who needed further evaluation were referred to the Ophthalmology Clinic of Imam Khomeini Hospital. RESULTS: Regarding the prevalence of refractive errors, 32 (40.5%) subjects had one or a combination of refractive errors, the most common of which was astigmatism (36.7%), followed by amblyopia (15.1%). The most common type of strabismus was latent strabismus (heterophoria) (88.6%), followed by exophoria (81%). Moreover, 3 (3.7%) cases had nystagmus. A significant difference was observed between the prevalence of amblyopia and the degree of hearing loss (P = 0.026), and no significant difference was detected in other cases. CONCLUSION: As evidenced by the obtained results, refractive errors, amblyopia, strabismus, and low vision are more prevalent among deaf and hearing-impaired children compared to normal children because deaf and hearing-impaired children are not able to convey their vision problems and need to compensate for their poor hearing with an enhanced sense of sight, inattention to these disorders can present these children with serious educational and social problems. Therefore, eye screening examinations are of paramount importance in deaf and hearing-impaired children.

Long-term visual outcomes in spasmus nutans.

BACKGROUND: The long-term visual outcomes in spasmus nutans patients is largely unknown. The purpose of this study was to characterize visual outcomes and identify comorbid ophthalmic conditions in patients with spasmus nutans. METHODS: We retrospectively reviewed the charts of consecutive patients diagnosed with spasmus nutans between 2000 and 2020. Demographic information, ophthalmic characteristics, and neuroimaging results were assessed over time. RESULTS: Of the 32 patients included in the study, 13 (41%) were female. Underlying medical conditions included a diagnosis of Trisomy 21 in 6 (19%) and prematurity in 8 (25%). Twenty-one patients (66%) self-reported as a race other than Caucasian. 18 patients (56%) had non-private health insurance and 1 (3%) was uninsured. Mean age at diagnosis and resolution were 16 months (range 45 months) and 48 months (range 114 months), respectively. All 32 patients had nystagmus, 31 (97%) had head nodding and 16 (50%) had ocular torticollis. Mean follow-up was 66 months (range 185 months). On initial presentation, 6/32 (19%) had an amblyogenic refractive error and mean best-corrected visual acuity (BCVA) in the better-seeing eye was 0.78 Logarithm of the Minimum Angle of Resolution (LogMAR) (range 1.24). In a sub-analysis that included patients with > 1 exam (n = 23), 17/20 (85%) had an amblyogenic refractive error and mean BCVA in the better-seeing eye was 0.48 LogMAR (range 1.70). At the final exam, 12 patients had measurable stereopsis, eight had strabismus, and three had undergone strabismus surgery. Eight patients required treatment for amblyopia. CONCLUSIONS: We found a high prevalence of amblyogenic refractive error, strabismus and amblyopia among patients with spasmus nutans. Children with spasmus nutans benefit from ongoing ophthalmic follow-up until they are past the amblyopic age range, even after resolution of nystagmus.

Can viewing a 3D movie improve visual function in children with a history of amblyopia and neurotypical children?: A pilot study.

PURPOSE: The aim of this pilot study was to determine whether viewing an immersive 3D movie with large disparities in a cinema resulted in improved visual acuity (VA), stereoscopic depth perception (ST), and improved eye alignment in residual amblyopic children and children without amblyopia. METHODS: A total of 24 children aged between 5 and 12 years with a history of anisometropic and/or strabismic amblyopia, that had been previously treated and who currently have residual amblyopia (N = 14), and in children with typical development without amblyopia (N = 10) viewed the movie in 3D Sing 2 in a cinema for 110 minutes. Visual acuity, stereoacuity and ocular deviation were assessed before viewing the movie, and three months later. Stereoacuity and ocular deviation were also measured immediately after viewing the movie. RESULTS: We observed an improvement in visual acuity in the non-dominant (amblyopic) eye 3 months after viewing the movie in the amblyopic group (P<0.001). Stereopsis improved immediately after viewing the movie (P = 0.02), and after 3 months by ≈ 40% (P = 0.01). Moreover, improvements in stereopsis were also observed in children without amblyopia (P = 0.04). No significant changes in ocular deviation were observed in either group. CONCLUSIONS: These pilot results suggest that brief exposure to large disparities by viewing a 3D movie in a cinema can help to improve stereopsis and visual acuity in children aged 5‒12 years with previously treated amblyopia, and provide a rationale for a randomized clinical trial.

Prevalence and characteristics of amblyopia, strabismus, and refractive errors among patients aged 3-16 years in Shanghai, China: a hospital-based population study.

BACKGROUND: Functional visual impairments in children are primarily caused by amblyopia or strabismus. This study aimed to determine the prevalence and clinical profile of amblyopia and strabismus among individuals aged 3-16 years in Shanghai, China. METHODS: From February 2023 to February 2024, this hospital-based, cross-sectional study included data of children who visited the Ophthalmology Department of Shanghai General Hospital. Comprehensive ocular examinations included visual acuity measurement after cycloplegic refraction, slit lamp examination, cover test, and dilated fundus examination. Descriptive statistics were performed to estimate the proportion and clinical characteristics of amblyopia and strabismus. RESULTS: A total of 920 children were enrolled in our study. Among them, 223 (24.24%) children were identified as amblyopia. Unilateral amblyopia occupied 57.85%, and bilateral amblyopia occupied 42.15%. Most participants were within the age range of 5-10 years (75.97% for unilateral amblyopia, and 70.21% for bilateral amblyopia). Anisometropia was the primary cause of unilateral amblyopia (68.99%). Most amblyopic children have high hyperopia (38.76% for unilateral amblyopia, and 39.89% for bilateral amblyopia). 30 (3.26%) children were diagnosed with strabismus, and 19 (63.3%) of them were aged 5-10 years. Seven of the children had both strabismus and amblyopia. CONCLUSION: The proportion of patients with amblyopia and strabismus was determined as 24.24% and 3.26% in our study. Anisometropia was the leading cause of unilateral amblyopia, whereas high hyperopia was a crucial refractive error in the amblyopic population. These findings shed light on further longitudinal studies targeting the age-related changes in amblyopia, strabismus and refraction errors. Therefore, efforts should be made to manage uncorrected refractive errors, amblyopia, and strabismus among children in Shanghai.

Effectiveness of optical treatment in amblyopia and validation of measuring spectacle compliance with the ODM.

PURPOSE: The improvement in visual acuity (VA) was determined during optical treatment in children with amblyopia before their participation in a randomised clinical trial comparing the effect of dichoptic video gaming using virtual reality goggles with occlusion therapy. METHODS: Children aged 4-12 years with an interocular VA difference ≥0.20 logMAR and an amblyogenic factor: strabismus <30Δ, ≥1.00 D anisometropia, astigmatism ≥1.50 D and/or hypermetropia ≥1.50 D were eligible for 16 weeks of optical treatment. Children with previous amblyopia treatment were excluded. Compliance with spectacle wear was measured electronically over 1 week using the occlusion dose monitor (ODM). The reliability of these measurements was verified. The main outcome was an increase in amblyopic eye VA from baseline to 16 weeks. RESULTS: Sixty-five children entered the optical treatment period. Mean age was 6.0 ± 2.2 years (range: 4-12 years; IQR 4.5-6.7 years). Amblyopia was caused by anisometropia in 53 (82%) children, strabismus in 6 (9%) and combined mechanism in 6 (9%). After optical treatment, mean VA improved by 0.20 logMAR (SD 0.28; p < 0.001) and 0.07 in the amblyopic and fellow eye, respectively (SD 0.20; p = 0.03). This resulted in 24 children (37%) with an interocular VA difference <0.20 logMAR and in 17% of children with VA at the start of 0.30 logMAR or worse. Poor VA in the amblyopic eye at baseline (p = 0.001) and high anisometropia (p = 0.001) were associated with VA improvement. On average, spectacles were worn 9.7 ± 2.4 h/day (range: 2.3-13.6 h); mean compliance was 73% ± 18% of estimated wake time. Only ambient temperature ≥ 31°C or when spectacles were worn on top of the head prevented a reliable ODM measurement. CONCLUSIONS: VA improved by two lines resulting in more than a third of the children being treated sufficiently with spectacles alone and no longer being classified as amblyopic. The ODM proved to be a reliable method of measuring compliance with spectacle wear.

Extended optical treatment versus early patching with an intensive patching regimen in children with amblyopia in Europe (EuPatch): a multicentre, randomised controlled trial.

BACKGROUND: Amblyopia, the most common visual impairment of childhood, is a public health concern. An extended period of optical treatment before patching is recommended by the clinical guidelines of several countries. The aim of this study was to compare an intensive patching regimen, with and without extended optical treatment (EOT), in a randomised controlled trial. METHODS: EuPatch was a randomised controlled trial conducted in 30 hospitals in the UK, Greece, Austria, Germany, and Switzerland. Children aged 3-8 years with newly detected, untreated amblyopia (defined as an interocular difference ≥0·30 logarithm of the minimum angle of resolution [logMAR] best corrected visual acuity [BCVA]) due to anisometropia, strabismus, or both were eligible. Participants were randomly assigned (1:1) via a computer-generated sequence to either the EOT group (18 weeks of glasses use before patching) or to the early patching group (3 weeks of glasses use before patching), stratified for type and severity of amblyopia. All participants were initially prescribed an intensive patching regimen (10 h/day, 6 days per week), supplemented with motivational materials. The patching period was up to 24 weeks. Participants, parents or guardians, assessors, and the trial statistician were not masked to treatment allocation. The primary outcome was successful treatment (ie, ≤0·20 logMAR interocular difference in BCVA) after 12 weeks of patching. Two primary analyses were conducted: the main analysis included all participants, including those who dropped out, but excluded those who did not provide outcome data at week 12 and remained on the study; the other analysis imputed this missing data. All eligible and randomly assigned participants were assessed for adverse events. This study is registered with the International Standard Randomised Controlled Trial Number registry (ISRCTN51712593) and is no longer recruiting. FINDINGS: Between June 20, 2013, and March 12, 2020, after exclusion of eight participants found ineligible after detailed screening, we randomly assigned 334 participants (170 to the EOT group and 164 to the early patching group), including 188 (56%) boys, 146 (44%) girls, and two (1%) participants whose sex was not recorded. 317 participants (158 in the EOT group and 159 in the early patching group) were analysed for the primary outcome without imputation of missing data (median follow-up time 42 weeks [IQR 42] in the EOT group vs 27 weeks [27] in the early patching group). 24 (14%) of 170 participants in the EOT group and ten (6%) of 164 in the early patching group were excluded or dropped out of the study, mostly due to loss to follow-up and withdrawal of consent; ten (6%) in the EOT group and three (2%) in the early patching group missed the 12 week visit but remained on the study. A higher proportion of participants in the early patching group had successful treatment (107 [67%] of 159) than those in the EOT group (86 [54%] of 158; 13% difference; p=0·019) after 12 weeks of patching. No serious adverse events related to the interventions occurred. INTERPRETATION: The results from this trial indicate that early patching is more effective than EOT for the treatment of most children with amblyopia. Our findings also provide data for the personalisation of amblyopia treatments. FUNDING: Action Medical Research, NIHR Clinical Research Network, and Ulverscroft Foundation.

Reduced Retinal Vascular Density and Skeleton Length in Amblyopia.

Purpose: This study aimed to investigate the possible relationship between retinal vascular abnormalities and amblyopia by analyzing vascular structures of fundus images. Methods: In this observational study, retinal fundus images were collected from 36 patients with unilateral amblyopia, 33 patients with bilateral amblyopia, and 36 healthy control volunteers. We developed a customized training algorithm based on U-Net to digitalize the vasculature in the fundus images to quantify vascular density (area and fractal dimension), skeleton length, and number of bifurcation points. For statistical comparisons, this study divided participants into two groups. The amblyopic eyes and the fellow eyes of patients with unilateral amblyopia formed the paired group, while bilateral amblyopic patients and healthy controls formed the independent group. Results: In the paired group, the vascular area (P = 0.007), vascular fractal dimension (P = 0.007), and vascular skeleton length (P = 0.002) of the amblyopic eyes were significantly smaller than those of the fellow eyes. In the independent group, significant decreases in the vascular fractal dimension (P = 0.006) and skeleton length (P = 0.048) were observed in bilateral amblyopia compared to control. The vascular area was also significantly correlated with best-corrected visual acuity in amblyopic eyes. Conclusions: This study demonstrated that retinal vascular density and skeleton length in amblyopic eyes were significantly smaller compared to control, indicating an association between the changes in retinal vascular features and the state of amblyopia. Translational Relevance: Our algorithm presents amblyopic retinal vascular changes that are more biologically interpretable for both clinicians and researchers.