Childhood amblyopia: current management and new trends

Efficacy of Amblyopia Treatments in Children Up to Seven Years Old: A Systematic Review

Amblyopia is a neurodevelopmental disorder of the visual system that impairs the vision of millions of children worldwide. Amblyopia is best treated within the sensitive period of visual development when a child is up to seven years of age. Currently, the gold standard for early treatment of childhood amblyopia is patching, with new treatments emerging in recent years. We aim to evaluate the effectiveness of these newly developed treatments for amblyopia in children aged seven years and younger while comparing them to the current industry standard of patching. We searched online databases including PubMed, Google Scholar, and Cochrane Library for randomized controlled trials (RCTs), systematic reviews, meta-analyses, and narrative reviews relating to amblyopia treatment in children aged seven and younger. We only included articles and studies completed within the last five years and those written in the English language. After compiling a list of 297 articles, we removed duplicates, articles without an available full text, and those not relevant to our topic. Of the remaining 51 articles, we were left with 22 after reading abstracts and removing further irrelevant articles. We did a quality assessment on the remaining 22 articles and were left with 14 articles for our systematic review after removing eight low-quality articles. Of the 14 articles, we had eight RCTs, two systematic reviews, one comparative interventional study, and three narrative reviews. Seven of the articles contained data reinforcing the effectiveness of patching while comparing it to other treatment modalities. Three of the articles had data supporting spectacle correction, including a novel form called alternative flicker glass which delivers occlusion therapy via a spectacle frame with unique lenses, and ultimately deemed it at least as effective or more than patching. Data from three articles supported the use of surgery to successfully correct the angle of strabismus. Findings from five articles backed the use of pharmacologic therapy, specifically atropine when used alongside patching as a more effective alternative to patching solely. However, levodopa plus patching had no advantage over patching alone. Additionally, seven articles addressed the use of virtual reality (VR) and dichoptic therapy as prospective treatments for childhood amblyopia. VR therapy proved beneficial when used within one week after strabismus surgery. Dichoptic training was also effective in improving amblyopic-eye visual acuity when used on its own or in conjunction with spectacles. Furthermore, dichoptic movie therapy was found to be more effective than patching. Thus, we found multiple highly effective treatments for childhood amblyopia that are as effective or more than patching. Future studies should consider prescribing these treatments to larger cohorts while also performing a cost-benefit analysis for each treatment. In addition, more needs to be learned about the potential adverse side effects of these treatments, especially for pharmaceutical therapy.

Cost-effectiveness of screening for amblyopia among kindergarten children in China

Objective

Current cost-effectiveness analyses of amblyopia screening are mainly from western countries. It remains unclear whether it is cost-effective to implement a preschool amblyopia screening programme in China. Our study aimed to evaluate the cost-effectiveness of a hypothetical kindergarten-based amblyopia screening versus non-screening among 3-year-old children.

Methods

We developed a decision tree combined with a Markov model to compare the cost and effectiveness of screening versus non-screening for 3-year-old children from a third-party payment perspective. The primary outcomes were quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER). Costs were obtained from expert opinions in different regions of China. Transition probabilities and health utilities were mainly based on published literature and open sources. Sensitivity analyses were performed to assess the impact of parameters' uncertainty on results.

Results

Base-case analysis demonstrated that the ICER of screening versus non-screening was $17,466/QALY, well below the WTP threshold ($38,223/QALY) for China. One-way sensitivity analysis showed that the prevalence of amblyopia, the transition probability per year from untreated amblyopia to healthy, and the discount rate were the top three factors. The likelihood of cost-effectiveness of screening compared with non-screening was 92.56%, according to probabilistic sensitivity analysis. Scenario analysis also indicated that ICER was lower than the WTP threshold even if the time horizon was shortened or the screening was delayed to the age of 4 or 5.

Conclusions

Amblyopia screening could be considered a cost-effective strategy compared to non-screening for 3-year-old children in China. Screening for children at the age of 4 or 5 may even yield better results.

Prevalence and Pattern of Eye Disorders Among Primary Schoolchildren in Abakaliki, Nigeria: A Cross-Sectional Study

Background A child's learning ability depends on vision, and visual impairment negatively affects neurological, intellectual, and emotional development by limiting children's exposure to a range of experiences and information. This study aims to determine the prevalence and pattern of ocular morbidity among primary schoolchildren in Abakaliki and provide evidence that can be used in planning a school eye health program for the state. Methodology A school-based, cross-sectional study was conducted within the Abakaliki metropolis between January and April 2018 to determine the ocular health status of schoolchildren recruited using stratified random sampling. Data were analyzed using SPSS version 22 (IBM Corp., Armonk, NY, USA) and presented using descriptive statistics. Univariate analysis was performed to determine the association between dependent and independent variables, with the level of significance determined by a p-value <0.05 (95% confidence interval (CI)). Results A total of 553 schoolchildren aged 6-16 years were examined. The prevalence of eye disorders was 23.5%. Common disorders included refractive error (12.7%) and allergic eye disease (7.1%). Other findings included glaucoma suspect (15, 2.7%), infective conjunctivitis (1, 0.2%), amblyopia (3, 0.5%), cataract (1, 0.2%), and squint (1, 0.2%). The prevalence of visual impairment was 3.1%. Univariate analysis showed a significant association between ocular morbidity and attending private schools (95% CI = 6.5-11.1, p = 0.003). Conclusions Eye disorders such as uncorrected refractive error and allergic conjunctivitis were common among schoolchildren. School eye health programs can ensure that eye screening is done periodically, allowing for early detection, referral, and prompt treatment of eye diseases that can potentially cause visual impairment.

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

BACKGROUND

Amblyopia 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.

METHODS

Subjects 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.

RESULTS

The 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.

CONCLUSION

Longer 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.

Predicting ophthalmic clinic non-attendance using machine learning: Development and validation of models using nationwide data

BACKGROUND

Ophthalmic clinic non-attendance in New Zealand is associated with poorer health outcomes, marked inequities and costs NZD$30 million per annum. Initiatives to improve attendance typically involve expensive and ineffective brute-force strategies. The aim was to develop machine learning models to accurately predict ophthalmic clinic non-attendance.

METHODS

This multicentre, retrospective observational study developed and validated predictive models of clinic non-attendance. Attendance data for 3.1 million appointments from all New Zealand government-funded ophthalmology clinics from 2009 to 2018 were aggregated for analysis. Repeated ten-fold cross validation was used to train and optimise XGBoost and logistic regression models on several demographic and clinic-related variables. Models developed using the entire training set were compared with those restricted to regional subsets of the data.

RESULTS

In the testing data set from 2019, there were 407 574 appointments (median [range] age, 66 [0-105] years; 210 365 [51.6%] female) with a non-attendance rate of 5.7% (n = 23 309 missed appointments), XGBoost models trained on each region's data achieved the highest mean AUROC of 0.764 (SD 0.058) and mean AUPRC of 0.157 (SD 0.072). XGBoost performed better than logistic regression (mean AUROC = 0.756, p = 0.002). Training individual XGBoost models for each region led to better performance than training a single model on the complete nationwide dataset (mean AUROC = 0.754, p = 0.04).

CONCLUSION

Machine learning algorithms can predict ophthalmic clinic non-attendance with relatively basic demographic and clinic data. These findings suggest further research examining implementation of such algorithms in scheduling systems or public health interventions may be useful.

Parents' Awareness, Knowledge, and Perception of Amblyopia in Children: A Study in Jazan Region, Saudi Arabia

Background Amblyopia is a vision disorder that results from a development problem in the brain rather than a neurological disease in the eye. The condition causes reduced visual acuity in one or both eyes due to the brain's inability to process inputs, rather than a structural abnormality. This study aims to assess parents' awareness, knowledge, and perception of amblyopia in their children in the Jazan region, Saudi Arabia. Methods This is a cross-sectional study that used an electronic questionnaire consisting of five main sections to assess the level of awareness of amblyopia among parents in the Jazan region. The Statistical Package for Social Sciences (SPSS v.25, IBM Corp., Armonk, NY, USA) was utilized to input the data. The degree to which participants' level of awareness was related to variables such as age, gender, and educational level was assessed through the chi-square test (χ2), and any values that scored p-values under 0.05 were deemed statistically significant. Results The analysis included 572 participants, 395 mothers (69.0%) and 177 fathers (31.0%). The age groups of the participants were divided into 36-45 years (38.0%), 26-35 years (36.0%), and above 46 years (17.0%). Out of the total, 36 participants (6.0%) had a history of amblyopia, and 73 (13.0%) had a child who suffered from amblyopia. The findings showed that only 18 participants (3.1%) had a good awareness of amblyopia, while 242 (42.3%) had a fair level of awareness. Most participants, 312 (54.5%), were classified as having a poor awareness level of amblyopia. Parents with postgraduate degrees, those with prior awareness, and parents whose children had eye diseases demonstrated higher levels of good awareness. However, gender, age, and residency did not have significant associations with awareness levels. Conclusion While parents must be involved in managing amblyopia, our research found that more than half of the parents surveyed had a limited understanding of various aspects of the disease, which can cause permanent damage to their child's vision. Therefore, we recommend implementing health education programs to increase awareness and knowledge about amblyopia in Jazan.

Clinical assessment, investigation, diagnosis and initial management of cerebral visual impairment: a consensus practice guide

Cerebral Visual Impairment (CVI) is a common condition in the UK. Patients with conditions associated with CVI are frequently seen in paediatric ophthalmology clinics offering eye care professionals an opportunity to identify children proactively. In most cases CVI occurs as part of a neurodevelopmental condition or as a feature of multiple and complex disabilities. However, CVI can also be seen in children with apparently typical development. In some cases, high contrast visual acuity is normal and in other cases severely impaired. As such, identification of CVI requires evaluation of aspects of visual performance beyond high contrast acuity and consideration that visual function of those with CVI may fluctuate. Few paediatric ophthalmologists have received formal training in CVI. The detection and diagnosis of CVI varies across the UK and patients report hugely different experiences. A diagnosis of CVI is made based on professional clinical judgement and it is recognised that individual perspectives and local practice in the specific methodologies of assessment will vary. A systematic review and survey of professionals is underway to attempt to reach agreement on diagnostic criteria. Nonetheless, established pathways and published protocols can offer guidance on how a paediatric ophthalmology service can approach assessment of the child with suspected CVI. The purpose of this paper is to present a summary of research and clinical practice methods for detecting and diagnosing CVI in a paediatric ophthalmology outpatient setting. It represents current understanding of the topic and acknowledges the evolving nature of both practice and the evidence-base. A rapid literature review was undertaken to identify articles relating to clinical investigation of children with CVI. A focus group of QTVI and subject matter experts from sight loss charities was undertaken to address areas which were not covered by the literature review.

Characteristics and Related Parameters of Quick Contrast Sensitivity Function in Chinese Ametropia Children

PURPOSE

To investigate the characteristics of quick contrast sensitivity function (qCSF) and its related parameters in Chinese ametropia children.

METHODS

This case series study enrolled 106 eyes of 53 children (male/female=29/24, age: 9.04±2.06 years). Examinations included manifest refraction, axial length, corneal curvature, and monocular and binocular qCSF readings without refractive correction (area under log CSF [AULCSF], CSF acuity, and contrast sensitivity [CS] at 1.0 to 18.0 cpd). The subjects were divided into groups according to age and refractive parameters for analysis.

RESULTS

The mean spherical equivalent (SE), AULCSF, and CSF acuity of the test eyes were -0.94±1.53 D, 0.44±0.33, and 8.50±5.97 cpd, respectively. In the monocular qCSF comparison, the refraction sphere (RS) was the major factor correlated with qCSF readings (B=0.186, P =0.009 for AULCSF; B=0.543, P =0.019 for CSF acuity; generalized linear model). The three groups stratified by RS/SE (<-1.00D, -1.00D to 0D, and >0D) showed significant differences in CS at medium spatial frequencies (3.0 and 6.0 cpd; all P <0.05). In the low RS/SE group (within -1 to 0 D), the CS at 12.0 cpd was significantly lower than that in the hyperopia group (all P <0.05). Binocular qCSF readings were significantly correlated with those of the eyes with lower RS (all P <0.05).

CONCLUSION

RS and SE are the major contributing factors of qCSF without refractive correction in children. The CS at medium spatial frequencies decrease significantly as the RS/SE increase. In low myopia children, the CS at medium and high spatial frequencies are significantly decreased, providing practical value in visual function screening in children.

Amblyopia: A review of unmet needs, current treatment options, and emerging therapies

Amblyopia is a global public health issue with extensive, multifaceted impacts on vision and quality of life (QoL) for both patients and families. Geographical variation exists in the management of amblyopia, with traditional mainstay treatments, optical correction, and fellow eye occlusion most successful when implemented at an early age. In recent years, however, studies demonstrating meaningful improvements in older children and adults have challenged the concept of a complete loss of visual processing plasticity beyond the critical period of visual development, with growing evidence supporting the potential efficacy of emerging, more engaging, binocular therapies in both adults and children. Binocular approaches aim to restore deficits in amblyopia that extend beyond monocular visual acuity impairment, including binocular fusion and visuomotor skills. In view of this, incorporating outcome measures that evaluate the visual performance and functional ability of individuals with amblyopia will provide a clearer understanding of the effect of amblyopia on QoL and a more comprehensive evaluation of amblyopia therapies.

Cost-effectiveness of Universal School- and Community-Based Vision Testing Strategies to Detect Amblyopia in Children in Ontario, Canada

IMPORTANCE

Screening for amblyopia in primary care visits is recommended for young children, yet screening rates are poor. Although the prevalence of amblyopia is low (3%-5%) among young children, universal screening in schools and mandatory optometric examinations may improve vision care, but the cost-effectiveness of these vision testing strategies compared with the standard in primary care is unknown.

OBJECTIVE

To evaluate the relative cost-effectiveness of universal school screening and mandated optometric examinations compared with standard care vision screening in primary care visits in Toronto, Canada, with the aim of detecting and facilitating treatment of amblyopia and amblyopia risk factors from the Ontario government's perspective.

DESIGN, SETTING, AND PARTICIPANTS

An economic evaluation was conducted from July 2019 to May 2021 using a Markov model to compare 15-year costs and quality-adjusted life-years (QALYs) between school screening and optometric examination compared with primary care screening in Toronto, Canada. Parameters were derived from published literature, the Ontario Schedule of Benefits and Fees, and the Kindergarten Vision Testing Program. A hypothetical cohort of 25 000 children aged 3 to 5 years was simulated. It was assumed that children in the cohort had irreversible vision impairment if not diagnosed by an optometrist. In addition, incremental costs and outcomes of 0 were adjusted to favor the reference strategy. Vision testing programs were designed to detect amblyopia and amblyopia risk factors.

MAIN OUTCOMES AND MEASURES

For each strategy, the mean costs per child included the costs of screening, optometric examinations, and treatment. The mean health benefits (QALYs) gained were informed by the presence of vision impairment and the benefits of treatment. Incremental cost-effectiveness ratios were calculated for each alternative strategy relative to the standard primary care screening strategy as the additional cost required to achieve an additional QALY at a willingness-to-pay threshold of $50 000 Canadian dollars (CAD) ($37 690) per QALY gained.

RESULTS

School screening relative to primary care screening yielded cost savings of CAD $84.09 (95% CI, CAD $82.22-$85.95) (US $63.38 [95% CI, US $61.97-$64.78]) per child and an incremental gain of 0.0004 (95% CI, -0.0047 to 0.0055) QALYs per child. Optometric examinations relative to primary care screening yielded cost savings of CAD $74.47 (95% CI, CAD $72.90-$76.03) (US $56.13 [95% CI, $54.95-$57.30]) per child and an incremental gain of 0.0508 (95% CI, 0.0455-0.0561) QALYs per child. At a willingness-to-pay threshold of CAD $50 000 (US $37 690) per QALY gained, school screening and optometric examinations were cost-effective relative to primary care screening in only 20% and 29% of iterations, respectively.

CONCLUSIONS AND RELEVANCE

In this study, because amblyopia prevalence is low among young children and most children in the hypothetical cohort had healthy vision, universal school screening and optometric examinations were not cost-effective relative to primary care screening for detecting amblyopia in young children in Toronto, Canada. The mean added health benefits of school screening and optometric examinations compared with primary care screening did not warrant the resources used.

Strabismus and amblyopia in Africa - a systematic review and meta-analysis

The objective of this review was to estimate the prevalence of strabismus and amblyopia in Africa. A systematic online literature search was conducted for articles on strabismus and amblyopia in Africa. Meta-analysis was performed, using the Freeman-Tukey double arcsine transformation, to estimate the prevalence of strabismus and amblyopia in Africa. Subgroup analyses were conducted according to age, gender, study year, and type of amblyopia. Meta-regression was used to evaluate the influence of predetermined factors on the prevalence of amblyopia. 8 (1 population-based & 7 school-based) and 21 (3 population-based & 18 school-based) studies on strabismus and amblyopia with sample sizes of 22,355 and 46,841, respectively, were included in the review. Overall prevalence of strabismus in Africa was estimated to be 0.8% (95% CI: 0.4% - 1.4%); exotropia was 0.2% (95% CI: 0.1% - 0.5%) and esotropia was 0.5% (95% CI: 0.1% - 1.2%). Overall prevalence of amblyopia was estimated to be 0.6% (95% CI: 0.3% - 0.9%); refractive and strabismic amblyopia were 1.1% (95% CI: 0.2% - 2.5%) and 0.4% (95% CI: 0.2% - 0.6%), respectively. Prevalence estimate of amblyopia in males was 1.8% (95% CI: 0.7% - 3.3%) and in females was 1.3% (95% CI: 0.4% - 2.6%). There was a significant association between the prevalence of amblyopia and the type of amblyopia (p = .007) and the study year (p = .006). Although there appears to be a relatively low prevalence of strabismus and amblyopia in Africa, there is a dearth of well-designed population-based studies on strabismus and amblyopia in Africa, resulting in the lack of epidemiological information on strabismus and amblyopia within the general African population. Information about the prevalence of strabismus and amblyopia across Africa can inform policy making and design and implementation of public health intervention program.

Amblyopia: progress and promise of functional magnetic resonance imaging

Amblyopia is a neurodevelopmental disorder characterized by functional deficits in the visual cortex. Functional magnetic resonance imaging (fMRI) is the most commonly used neuroimaging technique for investigating amblyopia. Herein, we systematically searched a PubMed database from inception to December 2021 to highlight the current progress and promises about fMRI technology in amblyopia; amblyopia's neural mechanism, the comparison of different types of amblyopia, and the evaluation of the therapeutic effect were explored. Relevant articles published in English and appropriate cross-references were considered for inclusion, including basic studies, imaging techniques, clinical diagnostic and therapeutic studies, case series, and reviews.

Adverse Influences of Nonstrabismic Amblyopia on Quality of Life of Teenagers in China

The aim of this study was to explore the influences of nonstrabismic amblyopia on quality of life in adolescents. Health-related quality of life (HRQoL) scale, a multidimensional construct that indicates a fundamental health outcome, was used to measure physical and psychosocial functioning of the adolescents. Forty teenagers with nonstrabismic amblyopia and 40 control teenagers without nonstrabismic amblyopia were recruited between April 2019 and July 2021. The anthropometric measures, body image, physical activity outcome, and HRQoL scores including physical health, emotional functioning, social functioning, and school functioning were compared between the two groups. The results revealed that teenagers with nonstrabismic amblyopia had less weekly sedentary time (P < 0.001), weekly total steps (P < 0.001), and worse school functioning (P = 0.0211) than control teenagers. No significant difference was found in anthropometric measures and body image between the two groups (P > 0.05). This study implied the needs for teenagers with nonstrabismic amblyopia to enhance physical activities. Teachers and parents are encouraged to pay more attention to teenagers with nonstrabismic amblyopia to improve their school functioning.

Microvascular assessment of macula, choroid, and optic disk in children with unilateral amblyopia using OCT angiography

PURPOSE

To investigate the microvascular changes of macula, choroid, and optic disk in children with unilateral amblyopia.

METHODS

This prospective cross-sectional study involved 39 unilateral amblyopic children and 39 age- and sex-matched heathy participants who served as control. Vessel densities of the superficial and deep capillary plexuses (SCP and DCP), foveal avascular zone (FAZ) area, macular thickness, optic disk vessel density, retinal nerve fiber layer (RNFL) thickness, choriocapillaris vessel density, and subfoveal choroidal thickness were evaluated by OCT angiography (OCTA). Meanwhile, the correlations of microvascular perfusion and structural changes of macula, choroid, and optic disk were analyzed.

RESULTS

The vessel density of SCP and DCP in the whole macula in the amblyopic group was significantly lower than that in the control group after adjusting for age, axial length, and spherical equivalents (all P < 0.05). FAZ area, macular thickness, RNFL thickness, and the optic disk vessel density were not statistically different between the amblyopic group and the control group (all P > 0.05). Subfoveal choroidal thickness of amblyopic eyes was significantly higher than that of control eyes(P = 0.032). Choriocapillaris flow void (FV) in the amblyopic group was greater than that in the control group (P = 0.013). Significant differences were observed between the fellow eyes and the control eyes in choriocapillaris FV and subfoveal choroidal thickness (P = 0.011 and P = 0.042, respectively). Foveal SCP and DCP vessel density in all studied eyes were positively correlated with the whole macular thickness, respectively (r = 0.556 and r = 0.627, respectively, both P < 0.001). Whole SCP and DCP vessel density in the amblyopic eyes were negatively correlated with choriocapillaris FV (r = -0.723, P < 0.001; r = -0.512, P = 0.001, respectively).

CONCLUSION

Children with amblyopic eyes have attenuated macular and choriocapillaris perfusion. There is a need for future studies that will investigate the pathophysiology of amblyopia in children by OCTA.

Evaluation of Choroidal Vascular Index in Amblyopic Patients

Objectives:

To compare subfoveal choroidal thickness (SFCT) and choroidal vascular index (CVI) in patients with hyperopic refractive and strabismic amblyopia and healthy subjects.

Materials and Methods:

The study included 17 patients with strabismic amblyopia (Group 1), 29 patients with hyperopic refractive amblyopia (Group 2), and 16 eyes of 16 healthy volunteers (Group 3). Best corrected visual acuity was noted in all patients and volunteers. In addition to detailed anterior and posterior segment examinations, macular images were obtained by enhanced-depth imaging mode of optical coherence tomography (OCT). SFCT measurements were made from these images and CVI was calculated using the Image J program.

Results:

No significant difference was found between the groups in terms of age, gender, and intraocular pressure (p=0.27, 0.64, and 0.85, respectively). Mean BCVAs in Group 1 were 0.57±0.16 (0.3-0.8) in the amblyopic eyes, 0.94±0.08 (0.8-1.0) in the fellow eyes, and in Group 2 were 0.61±0.17 (0.2-0.8) in amblyopic eyes, 0.92±0.1 (0.8-1.0) in fellow eyes. BCVA in Group 3 was 1.0±0 (1.0-1.0). Mean SFCT of the amblyopic eyes in Groups 1 and 2 was 341.50±60.4 (277-481) and 370.06±65.3 (247-462), respectively, and in the healthy eyes of Groups 1 and 2 and Group 3 was 321.92±68.26 (251-440), 330.35±74.00 (194-502), and 327.62±40.79 (238-385), respectively. SFCT was significantly greater in the amblyopic eyes of Group 2 compared to Group 3 (p=0.01). Mean CVI was 0.681±0.032 (0.642-0.736) in the amblyopic eyes and 0.685±0.054 (0.587-0.788) in the fellow eyes of Group 1 patients; 0.664±0.033 (0.592-0.719) in the amblyopic eye and 0.707±0.039 (0.625-0.779) in the fellow eye in Group 2 patients; and 0.689±0.031 (0.612-0.748) in Group 3 patients. CVI was significantly lower in the amblyopic eyes of Group 2 compared with fellow eyes (p=0.02) and Group 3 (p=0.025).

Conclusion:

Morphological changes may be seen in the choroid in amblyopic eyes. We observed that the choroidal stromal component is increased in hyperopic amblyopic patients especially.

An epidemiologic analysis of the association between eyelid disorders and ocular motility disorders in pediatric age

Aim of the study was to assess: (a) the prevalence and type of strabismus, ptosis and eyelid dynamic disorders features, (b) the prevalence of refractive errors, amblyopia and, (c) their association with ocular/systemic syndromes in a cohort of patients. This is a retrospective observational multicenter cohort study. Patients with coexisting ocular motility disorders, comitant and incomitant strabismus, ptosis and dynamic eyelid disorders who have never undergone surgery were enrolled throughout a 3-years a study period. 137 out of 19,089 patients were enrolled, of which 97 with uniocular and 40 with binocular disease. Isolated congenital ptosis was observed in 84 patients. A polymalformative syndrome was present in almost one third of cases, whilst among strabismus type, esotropia was slightly more prevalent. Most patients were hypermetropic. In monocular disease, myopia mainly affected older patients, who were characterized by a worse ptosis margin reflex distance and levator function, and significantly higher astigmatism. Amblyopia occurred in 67.4% of the study sub-population. Of note, in monocular disease this was mild in 25.8%, moderate in 24.2% and severe in 11.3% of cases, whilst in binocular disease it was mild in 25%, moderate in 41.7% and severe in 16.7%. All patients with coexisting eyelid and ocular motility dysfunctions in pediatric age need ophthalmologic and systemic evaluation to accurately assess amblyopia, refractive errors and systemic/ocular disorders.

Can pattern electroretinography be a relevant diagnostic aid in amblyopia? - A systematic review

INTRODUCTION

Pattern Electroretinography (PERG) is a highly sensitive electrophysiological technique used as an indicator of changes in retinal macular area. Amblyopia seems to result from a cortical visual imbalance but changes at the retinal level may also be present. The purpose of this systematic review was to evaluate if there are any consistent changes described in the scientific literature in PERG responses of amblyopic eyes.

MATERIALS AND METHODS

Searches were conducted in PubMed and Embase databases, using the keywords "Electroretinography" and "Amblyopia", combined with MeSH or Emtree terms "Pattern Electroretinography", "amblyopia", "PERG" and "amblyopia". PERG P50-N95 amplitude and P50 latency were analysed as well as the methodology used.

RESULTS

A total of 234 articles were found and 6 articles were included for review. One of the articles reported results in adults and five of them in children. One of the articles in children reported no changes in either P50-N95 amplitude or P50 latency. All articles that described differences between the amblyopic eye and the normal eye found a decrease in P50-N95 amplitude and/or a delay in P50 latency.

CONCLUSIONS

This review shows promising findings for the use of PERG in amblyopia as an aid in the diagnostic protocol, since this technique may be able to detect an apparent functional impairment of the amblyopic eye.

Crowding changes appearance systematically in peripheral, amblyopic, and developing vision

Visual crowding is the disruptive effect of clutter on object recognition. Although most prominent in adult peripheral vision, crowding also disrupts foveal vision in typically developing children and those with strabismic amblyopia. Do these crowding effects share the same mechanism? Here we exploit observations that crowded errors in peripheral vision are not random: Target objects appear either averaged with the flankers (assimilation) or replaced by them (substitution). If amblyopic and developmental crowding share the same mechanism, then their errors should be similarly systematic. We tested foveal vision in children aged 3 to 8 years with typical vision or strabismic amblyopia and peripheral vision in typical adults. The perceptual effects of crowding were measured by requiring observers to adjust a reference stimulus to match the perceived orientation of a target “Vac-Man” element. When the target was surrounded by flankers that differed by ± 30°, all three groups (adults and children with typical or amblyopic vision) reported orientations between the target and flankers (assimilation). Errors were reduced with ± 90° differences but primarily matched the flanker orientation (substitution) when they did occur. A population pooling model of crowding successfully simulated this pattern of errors in all three groups. We conclude that the perceptual effects of amblyopic and developing crowding are systematic and resemble the near periphery in adults, suggesting a common underlying mechanism.

Factors contributing to household wealth inequality in under-five deaths in low- and middle-income countries: decomposition analysis

BACKGROUND

The burden of under-5 deaths is disproportionately high among poor households relative to economically viable ones in developing countries. Despite this, the factors driving this inequality has not been well explored. This study decomposed the contributions of the factors associated with wealth inequalities in under-5 deaths in low- and middle-income countries (LMICs).

METHODS

We analysed data of 856,987 children from 66,495 neighbourhoods across 59 LMICs spanning recent Demographic and Health Surveys (2010-2018). Under-5 mortality was described as deaths among live births within 0 to 59 months of birth and it was treated as a dichotomous variable (dead or alive). The prevalence of under-five deaths was stratified using household wealth status. A Fairlie decomposition analysis was utilized to investigate the relative contribution of the factors associated with household wealth inequality in under-5 deaths at p<0.05. The WHO health equity assessment toolkit Plus was used to assess the differences (D) ratios (R), population attributable risk (PAR), and population attributable fraction (PAF) in household wealth inequalities across the countries.

RESULTS

The proportion of children from poor households was 45%. The prevalence of under-5 deaths in all samples was 51 per 1000 children, with 60 per 1000 and 44 per 1000 among children from poor and non-poor households (p<0.001). The prevalence of under-5 deaths was higher among children from poor households than those from non-poor households in all countries except in Ethiopia, Tanzania, Zambia, Lesotho, Gambia and Sierra Leone, and in the Maldives. Thirty-four of the 59 countries showed significantly higher under-5 deaths in poor households than in non-poor households (pro-non-poor inequality) and no significant pro-poor inequality. Rural-urban contexts, maternal education, neighborhood socioeconomic status, sex of the child, toilet kinds, birth weight and preceding birth intervals, and sources of drinking water are the most significant drivers of pro-poor inequities in under-5 deaths in these countries.

CONCLUSIONS

Individual-level and neighbourhood-level factors were associated with a high prevalence of under-5 deaths among poor households in LMICs. Interventions in countries should focus on reducing the gap between the poor and the rich as well as improve the education and livelihood of disadvantaged people.

Canon CP-TX1 camera - As a screening tool for amblyogenic risk factors

Purpose:

To evaluate the Canon CP-TX1 camera as a screening tool for ARFs in a pediatric population and estimate the prevalence of ARFs.

Methods:

In a pediatric outpatient space, largely in the immunization clinic, after obtaining parental consent, we encouraged children to be photographed from a distance of 5 feet in a dim room by using a CP-TX1 camera with the red-eye reduction feature off. Based on the captured red reflex, children were labeled as normal (symmetrical red reflexes in the two eyes, with no visible crescents); all others were considered as abnormal or positive for ARFs. All photographed children were assessed by an optometrist/refractionist for VA by age-appropriate methods. Data were entered into a 2 × 2 contingency table on statpages.org, and diagnostic indices were calculated with 95%CI.

Results:

With a sample of 262 children, we obtained a sensitivity of 0.82, a specificity of 0.98, a positive predictive value of 0.92, a negative predictive value of 0.94, a positive likelihood ratio of 41.06, a negative likelihood ratio of 0.17, and a prevalence of 0.24 for ARFs

Conclusion:

CP-TX1 performed well as a screening tool to identify ARFs in children. Placing such a camera in an immunization clinic offers a chance to identify children with ARFs at a time when amblyopia is eminently reversible.

Strabismus and postural control: a systematic review

The primary aim of this systematic review is to evaluate how postural balance and visual system are related in cross-eyed patients. The secondary goal is to assess the benefits of eye realignment on motor skills and body balance. Analyzing two different approaches: surgical or conservative, a systematic literature search was conducted using PubMed-Medline, Google Scholar and Cochrane Central in order to identify randomized controlled trials, case series and case-control studies which contained clinical evaluation of balance in strabismic patients as well as re-evaluation after surgery or conservative treatments via posturography to evaluate surface, length and mean speed of the center of pressure (CoP). A total of 11 studies were included in this review. The MINORS score is used to assess the methodological quality of the included studies, and its mean value was 12.8 for non-comparative studies and 17.5 for comparative studies. The postural balance was lower in strabismic patients compared with the control group, with statically higher value (p < 0.05) of surface, length and mean speed of the CoP in the study group. All patients show improvement in stability after surgery, as surface, length and mean speed of the CoP decreased after surgery in all the studies with statistical significance (p < 0.05).

Binocular versus standard occlusion or blurring treatment for unilateral amblyopia in children aged three to eight years

BACKGROUND

Current treatments for amblyopia, typically patching or pharmacological blurring, have limited success. Less than two-thirds of children achieve good acuity of 0.20 logMAR in the amblyopic eye, with limited improvement of stereopsis, and poor adherence to treatment. A new approach, based on presentation of movies or computer games separately to each eye, may yield better results and improve adherence. These treatments aim to balance the input of visual information from each eye to the brain.  OBJECTIVES: To determine whether binocular treatments in children, aged three to eight years, with unilateral amblyopia result in better visual outcomes than conventional patching or pharmacological blurring treatment.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), MEDLINE, Embase, ISRCTN, ClinicalTrials.gov, and the WHO ICTRP to 19 November 2020, with no language restrictions.

SELECTION CRITERIA

Two review authors independently screened the results of the search for relevant studies. We included randomised controlled trials (RCTs) that enrolled children between the ages of three and eight years old with unilateral amblyopia. Amblyopia was classed as present when the best-corrected visual acuity (BCVA) was worse than 0.200 logMAR in the amblyopic eye, with BCVA 0.200 logMAR or better in the fellow eye, in the presence of an amblyogenic risk factor, such as anisometropia, strabismus, or both. To be eligible, children needed to have undergone cycloplegic refraction and  ophthalmic examination, including fundal examination and optical treatment, if indicated, with stable BCVA in the amblyopic eye despite good adherence with wearing glasses. We included any type of binocular viewing intervention, on any device (e.g. computer monitors viewed with liquid-crystal display shutter glasses; hand-held screens, including mobile phones with lenticular prism overlay; or virtual reality displays). Control groups received standard amblyopia treatment, which could include patching or pharmacological blurring of the better-seeing eye. We included full-time (all waking hours) and part-time (between 1 and 12 hours a day) patching regimens. We excluded children who had received any treatment other than optical treatment; and studies with less than 8-week follow-up.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The primary outcome of the review was the change from baseline of distance BCVA in the amblyopic eye after 16 (± 2) weeks of treatment, measured in logMAR units on an age-appropriate acuity test.

MAIN RESULTS

We identified one eligible RCT of conventional patching treatment versus novel binocular treatment, and analysed a subset of 68 children who fulfilled the age criterion of this review. We obtained data for the mean change in amblyopic eye visual acuity, adverse events (diplopia), and adherence to prescribed treatment at 8- and 16-week follow-up intervals, though no data were available for change in BCVA after 52 weeks. Risk of bias for the included study was considered to be low. The certainty of evidence for the visual acuity outcomes at 8 and 16 weeks of treatment and adherence to the study intervention was rated moderate using the GRADE criteria, downgrading by one level due to imprecision. The certainty of evidence was downgraded by two levels and rated low for the proportion of participants reporting adverse events due to the sample size.  Acuity improved in the amblyopic eye in both the binocular and patching groups following 16 weeks of treatment (improvement of -0.21 logMAR in the binocular group and -0.24 logMAR in the patching group, mean difference (MD) 0.03 logMAR (95% confidence interval (CI) -0.10 to 0.04; 63 children). This difference was non-significant and the improvements in both the binocular and patching groups are also considered clinically similar. Following 8 weeks of treatment, acuity improved in both the binocular and patching groups (improvement of -0.18 logMAR in the patching group compared to -0.16 logMAR improvement in the binocular-treatment group) (MD 0.02, 95% CI -0.04 to 0.08). Again this difference was statistically non-significant, and the differences observed between the patching and binocular groups are also clinically non-significant. No adverse event of permanent diplopia was reported. Adherence was higher in the patching group (47% of participants in the iPad group achieved over 75% compliance compared with 90% of the patching group).  Data were not available for changes in stereopsis nor for contrast sensitivity following treatment.

AUTHORS' CONCLUSIONS

Currently, there is only one RCT that offers evidence of the safety and effectiveness of binocular treatment. The authors are moderately confident that after 16 weeks of treatment, the gain in amblyopic eye acuity with binocular treatment is likely comparable to that of conventional patching treatment. However, due to the limited sample size and lack of long term (52 week) follow-up data, it is not yet possible to draw robust conclusions regarding the overall safety and sustained effectiveness of binocular treatment. Further research, using acknowledged methods of visual acuity and stereoacuity assessment with known reproducibility, is required to inform decisions about the implementation of binocular treatments for amblyopia in clinical practice, and should incorporate longer term follow-up to establish the effectiveness of binocular treatment. Randomised controlled trials should also include outcomes reported by users, adherence to prescribed treatment, and recurrence of amblyopia after cessation of treatment.

Practice patterns in the management of amblyopia among optometrists in Ghana

Despite internationally recognized guidelines, amblyopia management varies among eye care professionals worldwide. Hence, we sought to investigate the practice patterns of amblyopia management and the factors associated with the decision to treat amblyopia among optometrists in Ghana. A cross-sectional survey was conducted among registered optometrists in Ghana from January 2020 to October 2020. Data collection was done through the administration of online questionnaires via e-mail (google form). The structured questionnaires included demographic information, mode, and scope of practice, diagnostic criteria, examination procedures, treatment modalities, and prognosis. A p value of less than 0.05 was deemed statistically significant. The mean (±SD) age of all the 168 respondents was 32.6 (±6.1) years (range: 24-50 years). The majority of the optometrists (64.9%) treated amblyopia in their practice; with the most prevalent being refractive amblyopia (68.2%), followed by strabismic amblyopia (27.1%), then form-deprivation amblyopia (4.7%). Most (76.1%) amblyopic patients presented with symptomatic squinting. The most common ocular and medical history was anisometropia (90.0%), and the most common diagnostic procedures were patient history, visual acuity, and refraction. Optical correction (88.3%) was mainly prescribed for amblyopia treatment, followed by patching (58.5%). Nearly half of the respondent (45.0%) reported good prognosis after amblyopia treatment. After statistical adjustment, female optometrists were significantly associated with decreased odds of treating amblyopia (AOR = 0.36, p = .004). Refractive amblyopia is the main type of amblyopia managed by optometrists in Ghana. Hence, optical correction is the primary treatment regime. Current amblyopia management practice among optometrists adhere to recommended guidelines and our findings demonstrate uniformity in the standard of care.

Pinhole does not increase screening accuracy of detecting decreased best corrected visual acuity in schoolchildren

Background

Decreased best corrected visual acuity among children should be treated early in life, and vision screening in schoolchildren is an efficient and feasible selection for developing countries. Thus, the screening accuracy of different visual acuity tests is the key point for making vision screening strategies. The present study aims to explore the screening accuracy of uncorrected visual acuity (UCVA) and pin-hole corrected visual acuity (PCVA) using different vision chart in the detection of decreased best-corrected visual acuity (BCVA) among schoolchildren.

Methods

Grade one primary schoolchildren in urban Lhasa with data of UCVA using tumbling E chart (UCVAE), PCVA using tumbling E chart (PCVAE), UCVA using Lea Symbols chart (UCVAL), PCVA using Lea Symbols chart (PCVAL) and BCVA using Lea Symbols chart were reviewed. Decreased BCVA was defined as BCVA≤20/32(≥0.2 logMAR). Difference, reliability, and diagnostic parameters in the detection of decreased BCVA of different visual acuity results were analyzed.

Results

Overall, 1672 children aged 6.58 ± 0.44 years fulfilling the criteria. The prevalence of decreased BCVA was 6.8%. Although no significant differences were found between UCVAE vs UCVAL (p = .84, paired t-test) as well as PCVAE vs PCVAL (p = .24), the ICC between them was low (0.68 and 0.57, respectively). The average difference between BCVA and UCVAE, UCVAL, PCVAE, PCVAL was logMAR -0.08 (− 0.37, 0.21), − 0.08 (− 0.29, 0.17), − 0.05 (− 0.30, 0.19), − 0.06 (− 0.23, 0.12) using Bland–Altman method. The area under the receiver operating characteristic curve of UCVAE, PCVAE, UCVAL, PCVAL for the detection of decreased BCVA was 0.78 (0.73, 0.84), 0.76 (0.71, 0.82), 0.95 (0.94, 0.96), 0.93 (0.91, 0.95), respectively.

Conclusion

Pinhole does not increase the screening accuracy of detecting decreased BCVA in grade one primary schoolchildren. Visual acuity test using Lea Symbols is more efficient than Tumbling E in the screening of that age.

Trial registration

Data were maily from the Lhasa Childhood Eye Study which has finished the clinical registration on (ChiCTR1900026693).

Refractive error, risk of amblyopia and eye care services utilisation among Nunavik Inuit in Northern Canada

CLINICAL RELEVANCE

Nunavik Inuit patients, in Northern Canada, have a significant burden of refractive error. The frequency at which they access eye care is insufficient. This exposes children of this population to a substantial risk of refractive amblyopia.

BACKGROUND

No data are available on eye health and services among Nunavik Inuit in Quebec, Canada. This study aims to describe the prevalence of ametropias, risk of refractive amblyopia, and eye health services uptake amongst a sample of Nunavik Inuit.

METHODS

Retrospective cohort using data from electronic records of the sole government-contracted eye team travelling to all 14 Nunavik villages, from 2006 to 2018.

RESULTS

Some 26,541 examinations were analysed, with data from 6,341 patients (median age 27 years (IQR 30); 32% aged under 19 years; 60.3% female) representing 48% of the census population. Population weighted prevalence of ametropias was myopia 46.5% (95% CI 45.3 - 47.6), hyperopia 17.1% (95% CI 16.2 - 18.1), astigmatism 39.6% (95% CI 38.4 - 40.8) and presbyopia 30.0% (95% CI 28.9 - 31.0). Some 5.9% of patients aged 0-9 years present a risk of refractive amblyopia. Mean frequency of examinations for all ages was once per 4 years (95% CI 4.0 - 4.0) and for children aged 5 - 19 years, frequency was once per 4.8 years (95% CI 4.8 - 5.0). In 2018, 74% of patients who were prescribed spectacles purchased them, with a median time of procurement of 21 days (IQR 247, skewness 2.7).

CONCLUSION

There is a high prevalence of ametropias amongst the clinical population of Nunavik Inuit. Most patients needing spectacles obtain them within a few weeks. Frequency of eye health services is insufficient to meet recommended guidelines, especially in children, for whom the risk of refractive amblyopia is pervasive.

Evaluation of axial length to identify the effects of monocular 0.125% atropine treatment for pediatric anisometropia

The aim of the study is to determine the effects of monocular 0.125% atropine daily treatment on the longer axial length (AL) eyes in children with pediatric anisometropia. This was a retrospective cohort study. The charts of children with anisometropia (aged 6–15 years) who had a > 0.2-mm difference in AL between the two eyes were reviewed. Children who received monocular treatment of 0.125% atropine in the eye with longer AL were included for final analysis. The main outcome measure was the difference in AL between the two eyes after treatment. Regression analysis was used to model the changes in AL according to the time of treatment in both eyes. Finally, forty eyes in 20 patients (mean age 10.2 years) were included in the analyses. During the treatment period, AL was controlled in the treated eyes (p = 0.389) but elongated significantly in the untreated eyes (p < 0.001). The difference in AL between the treated and untreated eyes decreased from 0.57 to 0.22 mm (p < 0.001) after the 1-year treatment period. In the regression model, the best fit for the relationship between changes in AL and time during the treatment period in the treated eyes was the quadratic regression model with a concave function. In conclusion, these data suggest that 0.125% atropine daily is an effective treatment to reduce the interocular difference of AL in eyes with axial anisometropia. This pilot study provides useful information for future prospective and larger studies of atropine for the treatment of pediatric axial anisometropia.

Amblyopia and Routine Eye Exam in Children: Parent's Perspective

Amblyopia is a reduced best-corrected visual acuity of one or both eyes that cannot be attributed to a structural abnormality; it is a functional reduction in the vision of an eye caused by disuse during a critical period of visual development. It is considered the leading cause of visual defects in children. With early diagnosis and treatment, children with amblyopia can significantly improve their vision. However, if it is neglected and not treated during childhood, unfortunately, it permanently decreases vision. Therefore, prevention, detection, and treatment largely depend on parents. This article explores parents' perspectives on amblyopia and routine examination of their children's eyes. A cross-sectional study used an electronic questionnaire consisting of five main sections to assess the level of awareness of amblyopia among parents. As a result, a total of 325 participants were included in our analysis. 209 (64.3%) were mothers, and 116 (35/7%) were fathers. The age groups were 35-50 years of age (61.5%), 20-34 years (23.4%), and older than 50 years (15%). Participants with a history of amblyopia numbered 23 (7.1%), and 39 had an amblyopic child (12%). A good awareness level of amblyopia among parents was found in only 10 (3%) participants, a fair awareness level in 202 (62%), and 113 (35%) participants were classified as having a poor awareness level of amblyopia. Only 13.8% of the parents took their children for yearly routine eye exams, while the majority (72%) took their children only if they had a complaint, and 14.2% took them for eye checkups only before school entry. In conclusion, parents' awareness of amblyopia in Tabuk City, KSA, was low. In addition, a limited proportion of parents reported consistently taking their children for routine eye exams. Therefore, raising awareness should be considered in public education regarding the disease.

The Assessment of YouTube Videos as a Source of Information for Amblyopia Treatment

PURPOSE

To evaluate the efficiency of YouTube videos as a source of information for the treatment of amblyopia.

METHODS

The authors searched YouTube (Google) using the keywords "amblyopia treatment" and analyzed the first 200 most relevant videos. Videos were classified as useful or misleading by two independent ophthalmologists. Videos were scored on 5-point scales to evaluate global quality, reliability, and comprehensiveness. General characteristics, viewer interactions, and sources of videos were also recorded.

RESULTS

Eighty-seven of 200 videos were appropriate to be included in the current study. Fifty videos (57.5%) were classified as useful and 37 videos (42.5%) were classified as misleading. General characteristics and viewer interactions were not significantly different between useful and misleading videos (P > .05). The mean Global Quality Score, reliability, and comprehensiveness scores were 3.64 ± 1.1, 3.02 ± 1.0, and 2.74 ± 1.2 in useful videos and 2.03 ± 0.9, 2.08 ± 0.8, and 1.62 ± 0.7 in misleading videos, respectively (P < .05). The data suggested that most of the videos uploaded by university channels or non-profit professionals were useful (79.2%), whereas most of the videos uploaded by medical advertisements or for-profit companies were misleading (59.1%).

CONCLUSIONS

The results of the current cross-sectional study demonstrated that the number of useful videos for the treatment of amblyopia was higher on YouTube. However, there was still a significant number of misleading videos (42.5%). Therefore, more videos on amblyopia treatment that have sufficient reliability, quality, and comprehensiveness should be uploaded to YouTube. [J Pediatr Ophthalmol Strabismus. 2021;58(5):311-318.].

Community based vision screening in preschool children; performance of the Spot Vision Screener and optotype testing

BACKGROUND

Children's vision screening children commonly uses optotype-based visual acuity or instrument-based methods measuring amblyogenic risk factors (ARFs).

OBJECTIVE

To compare the performance of the Spot Vision Screener (SVS) (PediaVision, Welch Allyn, NY) and a nurse-administered visual acuity screen (NVAS) in identifying ARFs and decreased visual acuity.

METHODS

A prospective, cross-sectional population-based study of preschool children in South-East Queensland, Australia. Eligible participants had both forms of screening by trained community nurses. All children with an abnormal result by either method as well as a cohort of randomly selected children who passed both assessments were assessed at a tertiary paediatric ophthalmology clinic.

RESULTS

Over a 10 month period, 2237 children (mean age; 64.4 ± 4.0 months) were screened from 38 schools. 6.4% of children failed SVS and 8.3% failed NVAS (with 3.8% overlap, failing both). The positive predictive value (PPV) in identifying either ARFs and/or reduced VA for the SVS and NVAS was 70.4% (95% Confidence Interval (CI): 61.6%-78.2%) and 60.5% (95% CI: 52.6%-67.9%) respectively. Highest PPV to detect either ARFs and/or reduced VA was achieved by a 'hybrid' method by combining failed NVAS and failed SVS: 91.0% (95% CI: 82.4 to 96.3) but this would risk children with sight impairment being missed in the community.

CONCLUSION

To our knowledge, this is the first population-based study providing detailed comparative measures of diagnostic accuracy for NVAS and SVS in preschool children. One in ten preschool children failed one or both screens. A number of children who required ophthalmic intervention were missed if only one screening method was utilized.

Altered Effective Connectivity of Children and Young Adults With Unilateral Amblyopia: A Resting-State Functional Magnetic Resonance Imaging Study

The altered functional connectivity (FC) in amblyopia has been investigated by many studies, but the specific causality of brain connectivity needs to be explored further to understand the brain activity of amblyopia. We investigated whether the effective connectivity (EC) of children and young adults with amblyopia was altered. The subjects included 16 children and young adults with left eye amblyopia and 17 healthy controls (HCs). The abnormalities between the left/right primary visual cortex (PVC) and the other brain regions were investigated in a voxel-wise manner using the Granger causality analysis (GCA). According to the EC results in the HCs and the distribution of visual pathways, 12 regions of interest (ROIs) were selected to construct an EC network. The alteration of the EC network of the children and young adults with amblyopia was analyzed. In the voxel-wise manner analysis, amblyopia showed significantly decreased EC between the left/right of the PVC and the left middle frontal gyrus/left inferior frontal gyrus compared with the HCs. In the EC network analysis, compared with the HCs, amblyopia showed significantly decreased EC from the left calcarine fissure, posterior cingulate gyrus, left lingual gyrus, right lingual gyrus, and right fusiform gyrus to the right calcarine fissure. Amblyopia also showed significantly decreased EC from the right inferior frontal gyrus and right lingual gyrus to the left superior temporal gyrus compared with the HCs in the EC network analysis. The results may indicate that amblyopia altered the visual feedforward and feedback pathway, and amblyopia may have a greater relevance with the feedback pathway than the feedforward pathway. Amblyopia may also correlate with the feedforward of the third visual pathway.

Temporal Characteristics of Visual Processing in Amblyopia

PURPOSE

Amblyopia affects not only spatial vision but also temporal vision. In this study, we aim to investigate temporal processing deficits in amblyopia.

METHODS

Twenty amblyopic patients (age: 27.0 ± 5.53 years, 15 males), and 25 normal observers (age: 25.6 ± 4.03 years, 15 males) were recruited in this study. Contrast thresholds in an orientation discrimination task in five target-mask stimulus onset asynchronies (SOA) conditions (16.7 ms, 33.4 ms, 50.0 ms, 83.4 ms, and ∞/no noise) were measured. An elaborated perceptual template model (ePTM) was fit to the behavioral data to derive the temporal profile of visual processing for each participant.

RESULTS

There were significant threshold differences between the amblyopic and normal eyes [F(1,43) = 10.6, p = 0.002] and a significant group × SOA interaction [F(2.75,118) = 4.98, p = 0.004], suggesting different temporal processing between the two groups. The ePTM fitted the data well (χ 2 test, all ps > 0.50). Compared to the normal eye, the amblyopic eye had a lower template gain (p = 0.046), and a temporal window with lower peak and broader width (all ps < 0.05). No significant correlation was found between the observed temporal deficits and visual acuity in amblyopia (ps > 0.50). Similar results were found in the anisometropic amblyopia subgroup. No significant difference was found between the fellow eyes of the monocular amblyopia and the normal eyes.

CONCLUSION

Amblyopia is less efficient in processing dynamic visual stimuli. The temporal deficits in amblyopia, represented by a flattened temporal window, are likely independent of spatial vision deficits.

Changes in the Brain Activity and Visual Performance of Patients with Strabismus and Amblyopia after a Compete Cycle of Light Therapy

This research assesses the brain activity and visual performance at baseline and after light therapy (LTH), of seventeen patients with strabismus and amblyopia (SA), and eleven healthy controls (HCs) from Querétaro, México. Quantitative electroencephalogram analysis (qEEG) was used to record the brain activity, and clinical metrics such as the visual acuity, angle of deviation, phoria state, stereopsis, and visual fields determined the visual performance. Results showed a constant higher alpha-wave frequency for HCs. Low voltages remained negative for HCs and positive for SA patients across stimulation. After LTH, high voltage increased in SA patients, and decreased in HCs. A second spectral peak, (theta-wave), was exclusively recorded in SA patients, at baseline and after LTH. Positive Spearman correlations for alpha-wave frequency, low and high voltages were only seen in SA patients. Synchronized brain activity was recorded in all SA patients stimulated with filters transmitting light in the blue but not in the red spectrum. Enhancement in the visual performance of SA patients was found, whereas deterioration of the phoria state and a decrease in the amount of stereopsis was seen in HCs. To conclude, only a suffering brain and a visual pathway which needs to be enabled can benefit from LTH.

Analysis of the potential impact of strabismus with and without amblyopia on visual-perceptual and visual-motor skills evaluated using TVPS-3 and VMI-6 tests

PURPOSE

To investigate the potential impact of strabismus and amblyopia on visual-perceptual skills (VPS) and visual-motor skills (VMS) of patients according to the type of strabismus, visual acuity (VA), state of binocularity, and sex.

METHODS

This observational, transverse, prospective study analyzed a sample of 146 children with strabismus (88 male and 58 female) aged 5-15 years from Querétaro, México. To determine the strabismus type, we considered the deviation direction, frequency, binocularity state, and associated and dissociated elements. VPS and VMS were evaluated using the Test of Visual-Perceptual Skills 3rd ed. (TVPS-3) and Visual-Motor Integration Test of Beery 6th ed. (VMI-6).

RESULTS

Sex was the main variable associated with the performance of the analyzed patients on TVPS-3 and VMI-6 (p<0.05); boys obtained better scores than girls in all evaluated aspects. Stereopsis was not a determinant of the patients' performance level but was associated with the far and near angles of deviation in both types of strabismus, esotropia and exotropia. Amblyopia was associated with the spatial relationship (p=0.001) and visual closure abilities (p=0.044). Form constancy skill scores diminished in both types of strabismus (esotropia: p=0.011; exotropia: p=0.004), and VMS were the most affected in patients with strabismus.

CONCLUSIONS

The performance of patients with strabismus with and without amblyopia on TVPS-3 and VMI-6 suggests that they adopt a mechanism to compensate for the impact of strabismus on their VPS and VMS.

Comparison between binocular therapy and patching for treatment of amblyopia: a meta-analysis of randomised controlled trials

Several studies have compared binocular therapy and patching for the treatment of amblyopia. However, most of them involved a small number of cases and reported controversial results. Thus, the benefit of binocular therapy remains to be confirmed. We conducted a meta-analysis to evaluate the efficacy of binocular therapy versus patching and to testify whether binocular therapy could become supplementary method in children with amblyopia. Randomised controlled trials that evaluated the efficacy of binocular therapy for amblyopia versus patching were identified using PubMed, Embase, Cochrane Library, Ovid, Web of Science, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform. Data screening, extraction and quality assessment were performed independently by two researchers. Six trials were identified and analysed to compare binocular therapy (708 eyes) with patching (664 eyes) for change in best-corrected visual acuity and stereoacuity. Efficacy estimates were evaluated by standard mean difference (SMD) and 95% CI. The best-corrected visual acuity in binocular group was better than that of in patching group (SMD=-0.21 logarithm of the minimum angle of resolution (log MAR), 95% CI of -0.50 to 0.08 log MAR, p=0.003). The results showed statistically significant difference in the change of best-corrected visual acuity between the groups, but not in stereoacuity. Binocular therapy may be a promising treatment of conditions affecting visual acuity, and could be applied as a supplementary method to patching for amblyopia in clinical practice. The present analysis showed that some children with amblyopia may benefit from binocular therapy. Nevertheless, larger randomised controlled clinical trials are required to confirm these findings.

Adherence to home-based videogame treatment for amblyopia in children and adults

Clinical relevance: Home-based videogame treatments are increasingly popular for amblyopia treatment. However, at-home treatments tend to be done in short sessions and with frequent disruptions, which may reduce the effectiveness of binocular visual stimulation. These treatment adherence patterns need to be accounted for when considering dose-response relationships and treatment effectiveness.Background: Home-based videogame treatments are increasingly being used for various sensory conditions, including amblyopia ('lazy eye'), but treatment adherence continues to limit success. To examine detailed behavioural patterns associated with home-based videogame treatment, we analysed in detail the videogame adherence data from the Binocular tReatment of Amblyopia with VideOgames (BRAVO) clinical trial (ACTRN12613001004752).Methods: Children (7-12 years), teenagers (13-17 years) and adults (≥ 18 years) with unilateral amblyopia were loaned iPod Touch devices with either an active treatment or placebo videogame and instructed to play for a total of 1-2 hours/day for six weeks at home. Objectively-recorded adherence data from device software were used to analyse adherence patterns such as session length, daily distribution of gameplay, use of the pause function, and differences between age groups. Objectively-recorded adherence was also compared to subjectively-reported adherence from paper-based diaries.Results: One hundred and five of the 115 randomised participants completed six weeks of videogame training. Average adherence was 65% (SD 37%) of the minimum hours prescribed. Game training was generally performed in short sessions (mean 21.5, SD 11.2 minutes), mostly in the evening, with frequent pauses (median every 4.1 minutes, IQR 6.1). Children played in significantly shorter sessions and paused more frequently than older age groups (p < 0.0001). Participants tended to over-report adherence in subjective diaries compared to objectively-recorded gameplay time.Conclusion: Adherence to home-based videogame treatment was characterised by short sessions interspersed with frequent pauses, suggesting regular disengagement. This complicates dose-response calculations and may interfere with the effectiveness of treatments like binocular treatments for amblyopia, which require sustained visual stimulation.

Emerging therapies for amblyopia

Traditional therapies to treat amblyopia, such as optical correction or occlusion/penalization of the non-amblyopic eye, are efficacious but are not without limitations such as poor adherence and decreased success with increasing age. Recently, there has been an interest in new amblyopia therapies, some using binocular techniques, through a variety of platforms including video games, movies, and virtual reality. Overall, available efficacy results for these treatments are highly variable.

Prevalence of amblyopia and its determinants in a rural population: a population-based cross-sectional study

To determine the prevalence of amblyopia and its determinants in underserved rural villages of Iran. This population-based cross-sectional study was conducted in 3850 subjects selected from two underserved districts in the north (Kojur District, Nowshahr County, Mazandaran Province) and southwest (Shahyun District, Dezful County, Khuzestan Province) of Iran using multi-stage cluster sampling. The subjects underwent complete ophthalmic examinations including the measurement of uncorrected (UCVA) and best-corrected (BCVA) visual acuity, objective and subjective refraction, unilateral and alternate cover tests and ocular health examination. Amblyopia was defined as a reduction of BCVA to 20/30 or less in one eye or a 2-line interocular optotype acuity difference in the absence of any pathological factors. Of 3850 selected subjects, 3314 participated in the study (response rate = 86.08%). The mean age of the participants was 36.90 ± 20.21 years (range: 3-93 years). The prevalence and 95% confidence interval of total, bilateral, and unilateral amblyopia were 2.73% (2.17 to 3.38), 0.50% (0.28 to 0.83), and 2.23% (1.73 to 2.83), respectively. The most common type of amblyopia was anisometropic followed by strabismic and mixed. The lowest and highest prevalence was seen in the age group 6-20 years (1.36%; 0.65 to 2.49) and above 70 years (5.97%; 3.02 to 10.44), respectively. According to the results of multiple logistic regression analysis, compared to illiterate subjects, the odds ratio of amblyopia was 0.321 (P = .033) in subjects with High school education, 0.181 (P = .030) in subjects with secondary School education, and 0.486 (P = .041) in subjects with primary school education. The odds ratio of amblyopia for north villages residence vs southwest villages residence was 2.105 (P = .012). The odds ratio of amblyopia was 2.765 for age group>70 years vs. 6-20 years (P = .033). The prevalence of amblyopia was higher in north region, in participants with lower education level and older individuals. The high prevalence of amblyopia in older people may be due to the lack of screening programs in previous generations and consequently the lack of timely diagnosis and treatment.

A New Dichoptic Training Strategy Leads to Better Cooperation Between the Two Eyes in Amblyopia

Recent clinical trials failed to endorse dichoptic training for amblyopia treatment. Here, we proposed an alternative training strategy that focused on reducing signal threshold contrast in the amblyopic eye under a constant and high noise contrast in the fellow eye (HNC), and compared it to a typical dichoptic strategy that aimed at increasing the tolerable noise contrast in the fellow eye (i.e., TNC strategy). We recruited 16 patients with amblyopia and divided them into two groups. Eight patients in Group 1 received the HNC training, while the other eight patients in Group 2 performed the TNC training first (Phase 1) and then crossed over to the HNC training (Phase 2). We measured contrast sensitivity functions (CSFs) separately in the amblyopic and fellow eyes when the untested eye viewed mean luminance (monocularly unmasked) or noise stimuli (dichoptically masked) before and after training at a particular frequency. The area under the log contrast sensitivity function (AULCSF) of masked and unmasked conditions, and dichoptic gain (the ratio of AULCSF of masked to unmasked condition) were calculated for each eye. We found that both dichoptic training paradigms substantially improved masked CSF, dichoptic gain, and visual acuity in the amblyopic eye. As opposed to the TNC paradigm, the HNC training produced stronger effects on masked CSFs, stereoacuity, dichoptic gain, and visual acuity in the amblyopic eye. Interestingly, the second-phase HNC training in Group 2 also induced further improvement in the masked contrast sensitivity and AULCSF in the amblyopic eye. We concluded that the HNC training strategy was more effective than the TNC training paradigm. Future design for dichoptic training should not only focus on increasing the tolerable noise contrast in the fellow eye but should also "nurture" the amblyopic eye under normal binocular viewing conditions and sustained interocular suppression.

Long-term Effect of Intraocular Lens vs Contact Lens Correction on Visual Acuity After Cataract Surgery During Infancy: A Randomized Clinical Trial

Importance

Although intraocular lenses (IOLs) are often implanted in children, little is known whether primary IOL implantation or aphakia and contact lens correction results in better long-term visual outcomes after unilateral cataract surgery during infancy.

Objective

To compare long-term visual outcomes with contact lens vs IOL correction following unilateral cataract surgery during infancy.

Design, Setting, and Participants

This multicenter randomized clinical trial enrolled 114 infants with a unilateral congenital cataract who underwent cataract surgery with or without primary IOL implantation between 1 and 6 months of age. Data on long-term visual outcomes were collected when the children were age 10.5 years (July 14, 2015, to July 12, 2019) and analyzed from March 30 through August 6, 2019.

Interventions

Intraocular lens implantation at the time of cataract surgery.

Main Outcomes and Measures

Best-corrected visual acuity using the electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) testing protocol. Analysis was performed on an intention-to-treat basis.

Results

Best-corrected visual acuity was measured at age 10.5 years for 110 of the 114 patients (96%) enrolled as infants. The participants included 58 girls (53%) and 52 boys (47%). Overall, 27 of the children (25%) had good (logMAR 0.30 [Snellen equivalent, 20/40] or better) visual acuity in the treated eye (12 [22%] in the IOL group and 15 [27%] in the aphakia group), but 50 children (44%) had a visual acuity of logMAR 1.00 (Snellen equivalent, 20/200) or worse (25 [44%] in the IOL group and 25 [44%] in the aphakia group). The median logMAR acuity in the treated eye was similar in children randomized to receive an IOL at the time of cataract extraction (0.89; interquartile range [IQR], 0.33-1.43 [Snellen equivalent, 20/159]) and those who remained aphakic (0.86; IQR, 0.30-1.46 [Snellen equivalent, 20/145]) (IQR, 0.30-1.46; P = .82). Although the overall difference in median visual acuity between the 2 groups was small, the estimate was imprecise (99% CI for the difference in medians was -0.54 to 0.47).

Conclusions and Relevance

As in previous phases of the study, visual acuity outcomes were highly variable with only 27 children (25%) achieving excellent visual acuity in their treated eye and 50 children (44%) having poor vision in the treated eye. Implanting an IOL at the time of cataract extraction was neither beneficial nor detrimental to the visual outcome.

Trial Registration

ClinicalTrials.gov Identifier: NCT00212134.

A new visual acuity test on touchpad for vision screening in children

AIM

To validate a visual acuity (VA) test application on touchpad in the screening of pediatric population by comparing VA results obtained with conventional tests.

METHODS

A cohort of 101 patients, 44 girls and 57 boys with a median of 6.5 years old (3-10 years of age), presenting for eye examinations in Ophthalmology Department (Strasbourg, France) between November 1^st, 2018, and February 1^st, 2019 were enrolled. Monocular and binocular VA testing was performed on the subject using both a standard test and the touchpad application (Monoyer, "E" or, Pigassou depending of children's capacities). Patients were excluded if they were physically or mentally unable to use the touchpad. The duration of each tests, the painfulness, the comprehension, the attention of children during the test and test's preferences were also evaluated.

RESULTS

There was a good linear correlation and intra-class correlation coefficient [ICC=0.50 (0.34, 0.64) for binocular acuity, 0.74 (0.64, 0.82) for right eyes and 0.525 (0.37, 0.66) for left eye]. The standard errors of measurement were very low (0.08, 0.05, 0.08 for binocular VA, right eyes VA and left eyes VA, respectively). There was no difference between two tests for right eye (P=0.126), left eye (P=0.098) and binocular acuity (P=0.085). Non inferiority was proved for all binocular [-0.06 (-0.09, -0.03)], right eye [-0.04 (-0.07, -0.01)] and left eye [-0.06 (-0.09, -0.02)] VA. The sensitivity and specificity, which correspond to the ability for our app to detect amblyopia, were 92% and 80% respectively.

CONCLUSION

Our touchpad application represents an efficient and valid test of VA in children with a high specificity to detect visual impairment.

Prevalence and pattern of amblyopia in a rural hospital in Ghana

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

Polysialylated - neural cell adhesion molecule (PSA-NCAM) promotes recovery of vision after the critical period

Vision loss has long since been considered irreversible after a critical period; however, there is potential to restore limited vision, even in adulthood. This phenomenon is particularly pronounced following complete loss of vision in the dominant eye. Adult neural cell adhesion molecule (NCAM) knockout mice have an age-related impairment of visual acuity. The underlying cause of early deterioration in visual function remains unknown. Polysialylated (PSA) NCAM is involved in different forms of neural plasticity in the adult brain, raising the possibility that NCAM plays a role in the plasticity of the visual cortex, and therefore, in visual ability. Here, we examined whether PSA-NCAM is required for visual cortical plasticity in adult C57Bl/6J mice following deafferentation and long-term monocular deprivation. Our results show that elevated PSA in the contralateral visual cortex of the reopened eye is accompanied by changes in other markers of neural plasticity: increased brain-derived neurotrophic factor (BDNF) levels and degradation of perineuronal nets (PNNs). The removal of PSA-NCAM in the visual cortex of these mice reduced BDNF expression, decreased PNN degradation, and resulted in impaired recovery of visual acuity after optic nerve transection and chronic monocular deprivation. Collectively, our results demonstrate that PSA-NCAM is necessary for the reactivation of visual cortical plasticity and recovery of visual function in adult mice. It also offers a potential molecular target for the therapeutic treatment of cortically based visual impairments.

Vision training with VEP biofeedback in amblyopia after the critical period

PURPOSE

The purpose of this study was to investigate the benefits of vision training with visual evoked potentials (VEP) biofeedback in amblyopia after the critical period in 8 to 17-year (11.5 ± 3.1) old children.

METHODS

Ten participants with monocular amblyopia after the critical period underwent a 10-week, 20-session vision training program with the Retimax Vision Trainer device. During each session, the participants were instructed to be as focused as possible onto the fixation point in the middle of the screen. The size of the fixation point and the pitch of the background sound were changing according to VEP parameters and thus provided the participants real-time feedback of their visual performance.

RESULTS

The mean BCVA improvement across our group was 0.12 LogMAR (p < 0.01). There was also a significant increase in contrast sensitivity to the FACT chart across all spatial frequencies (all p < 0.05). Electrophysiologic data revealed higher steady-state visual evoked potentials (SS-VEP) amplitudes and correspondingly lower fixation point values in the last 2 weeks of training compared to the first 2 weeks (both p < 0.01). Due to unexplainably low VEP amplitude levels in later trainings compared to those in the beginning in two participants, we have not found a significant correlation between the increase in BCVA and the increase in SS-VEP amplitude (p = 0.88). At the follow-up at 2 and 12 months following the end of training, both BCVA and contrast sensitivity remained within the levels achieved at the end of training. In some participants, however, no improvement of BCVA was observed.

CONCLUSIONS

The tested vision training approach demonstrates modest but stable improvement of psychophysical parameters as well as objective characteristics in amblyopia after the critical period. Real-time SS-VEP can be used as an objective parameter to monitor participants' attention during vision training stimulation.

Scottish Pre-School Vision Screening - First 3 Years of National Data

INTRODUCTION

Pre-school orthoptic vision screening (POVS) was implemented by the Scottish government and is a standardised assessment to promote early detection of visual problems in children. The target conditions are amblyopia, refractive errors and strabismus. We present the preliminary findings for the first three years of the screening program.

METHODS

The data from POVS was collected retrospectively. The data includes screening years 2013 to 2016 inclusive. Data was collected from each health board in Scotland. We report the coverage, referral rate, true positives and positive predictive values.

RESULTS

A total of 167,962 children were due to have vision screening over the 3 screening years included in this paper. This figure does not include the children that opted out of the eye test (mean opt-out rate 1.8%) and children that already attend the hospital eye service (mean already attend rate 3.1%). The POVS program had a mean coverage of 85.5%, ranging from 63.7% to 94.8% between health boards. Over the 3 year screening period, the mean referral rate was found to be 17.9%. The mean true positive rate was 88.9%, and the mean positive predictive value was 86.9%.

CONCLUSION

The Scottish data set on pre-school orthoptic vision screening has shown excellent mean coverage. A consistently high true positive rate over the three screening years demonstrates it is a sensitive screening program, which is essential for the detection of visual problems in children.

Correlation between higher-order aberrations and visual acuity recovery (CoHORT) after spectacles treatment for pediatric refractive amblyopia: A pilot study using iDesign measurement

Purpose

To determine the correlation between higher-order aberrations (HOAs) and best-corrected visual acuity (BCVA) recovery speed after spectacles treatment using iDesign measurements in refractive amblyopic children.

Methods

This is a prospective case series. Children aged from 3 to 7 years with refractive amblyopia (Landolt C equivalent < 0.8) were recruited. All participants were followed for at least 6 months after full correction of the refraction error by spectacles. The HOAs were measured using iDesign before and after cycloplegia at first visit and at 3-month intervals. Then correlation between BCVA recovery after treatment for 6 months and HOAs was determined.

Results

We analyzed 24 eyes of 12 children (mean age, 4.5 years). Baseline mean BCVA was logarithm of minimal angle of resolution (logMAR) 0.335 (Landolt C equivalent 0.46), which improved to logMAR 0.193 (Landolt C equivalent 0.64) after treatment with full-correction spectacles for 6 months. The amblyopic eye BCVA recovery was negatively correlated with tetrafoil with/without cycloplegia (P = 0.006 and 0.022, respectively) and trefoil with cycloplegia (P = 0.049).

Conclusions

trefoil and tetrafoil measured with iDesign negatively correlates with the BCVA recovery speed of refractive amblyopic eyes after spectacles treatment in this pilot study. The current study results may aid in further investigation for diagnosis and treatment of refractory refractive and idiopathic amblyopia.

Effectiveness of a Binocular Video Game vs Placebo Video Game for Improving Visual Functions in Older Children, Teenagers, and Adults With Amblyopia: A Randomized Clinical Trial

Importance

Binocular amblyopia treatment using contrast-rebalanced stimuli showed promise in laboratory studies and requires clinical trial investigation in a home-based setting.

Objective

To compare the effectiveness of a binocular video game with a placebo video game for improving visual functions in older children and adults.

Design, Setting, and Participants

The Binocular Treatment of Amblyopia Using Videogames clinical trial was a multicenter, double-masked, randomized clinical trial. Between March 2014 and June 2016, 115 participants 7 years and older with unilateral amblyopia (amblyopic eye visual acuity, 0.30-1.00 logMAR; Snellen equivalent, 20/40-20/200) due to anisometropia, strabismus, or both were recruited. Eligible participants were allocated with equal chance to receive either the active or the placebo video game, with minimization stratified by age group (child, age 7 to 12 years; teenager, age 13 to 17 years; and adult, 18 years and older).

Interventions

Falling-blocks video games played at home on an iPod Touch for 1 hour per day for 6 weeks. The active video game had game elements split between eyes with a dichoptic contrast offset (mean [SD] initial fellow eye contrast, 0.23 [0.14]). The placebo video game presented identical images to both eyes.

Main Outcomes and Measures

Change in amblyopic eye visual acuity at 6 weeks. Secondary outcomes included compliance, stereoacuity, and interocular suppression. Participants and clinicians who measured outcomes were masked to treatment allocation.

Results

Of the 115 included participants, 65 (56.5%) were male and 83 (72.2%) were white, and the mean (SD) age at randomization was 21.5 (13.6) years. There were 89 participants (77.4%) who had prior occlusion. The mean (SD) amblyopic eye visual acuity improved 0.06 (0.12) logMAR from baseline in the active group (n = 56) and 0.07 (0.10) logMAR in the placebo group (n = 59). The mean treatment difference between groups, adjusted for baseline visual acuity and age group, was -0.02 logMAR (95% CI, -0.06 to 0.02; P = .25). Compliance with more than 25% of prescribed game play was achieved by 36 participants (64%) in the active group and by 49 (83%) in the placebo group. At 6 weeks, 36 participants (64%) in the active group achieved fellow eye contrast greater than 0.9 in the binocular video game. No group differences were observed for any secondary outcomes. Adverse effects included 3 reports of transient asthenopia.

Conclusions and Relevance

The specific home-based binocular falling-blocks video game used in this clinical trial did not improve visual outcomes more than the placebo video game despite increases in fellow eye contrast during game play. More engaging video games with considerations for compliance may improve effectiveness.

Trial Registration

anzctr.org.au Identifier: ACTRN12613001004752.

Selective serotonin reuptake inhibitors may lead to improved cataract surgery outcomes in patients with amblyopia

Purpose

To evaluate the effects of selective serotonin reuptake inhibitor (SSRI)/serotonin norepinephrine reuptake inhibitor (SNRI) medications in combination with cataract surgery in treating amblyopia in adult patients.

Patients and methods

A retrospective chart review study was conducted on patients who had undergone cataract surgery at the Johns Hopkins Hospital Wilmer Eye Institute. Six inclusion criteria were used to assess patient eligibility: 1) >18 years of age, 2) diagnosis of amblyopia, 3) diagnosis of cataract and treatment with surgery, 4) electronic medical record contains pre-surgery and post-surgery visual acuity (VA) measurements, 5) electronic medical record contains information on whether the patient was ever prescribed a SSRI/SNRI and the treatment duration, and 6) interocular VA difference of two lines or more on Snellen chart prior to cataract surgery. From each record, preoperative VA, postoperative VA, date of surgery, date at which postoperative VA was measured, and age at surgery were collected.

Results

A total of 237 patients were included, with 38 of them being on SSRI/SNRI. The mean improvement in VA after surgery was not significantly greater in patients on SSRI/SNRI (SSRI/SNRI: −0.276 logMAR, control: −0.192 logMAR, p=0.15). Multivariable regression was subsequently performed and while holding all other variables constant, demonstrated a statistically significant improvement in VA in patients on SSRI/SNRI (95% CI: −0.194, −0.0116, p=0.03). The regression analysis further demonstrated that advanced age has an adverse effect on the change in post-op VA (CI: 3.34×10⁻³ logMAR, 9.77×10⁻³ logMAR, p<0.005). Worse baseline VA is associated with a greater improvement in post-op VA (95% CI: −0.659 logMAR, −0.463 logMAR, p<0.005) but adverse effect on the absolute post-op VA (95% CI: 0.341 logMAR, 0.544 logMAR, p<0.005).

Conclusion

This study suggests that patients with amblyopia undergoing cataract surgery may potentially have a greater visual improvement when treated with SSRI/SNRIs.

The Role of Binocularity in Anisometropic Amblyopia

Anisometropic amblyopia is unilateral by definition and current treatment recommendations reflect that characteristic. However, recent research suggests a binocular component that deserves consideration. The aim of this review is to consider the levels of anisometropia deemed amblyogenic, and the cortical changes that occur in the presence of anisometropic amblyopia. Particular attention is given to cortical changes that impact the binocularity of these individuals. Knowledge of binocular deficits in anisometropic amblyopia has implications for current, accepted treatment regimens which are monocular in nature. Therefore, the integrity of binocular function in anisometropic amblyopia and its impact on the visual outcome will be evaluated. Given the rise in binocular treatments under clinical trial for amblyopia, this review also aims to evaluate the evidence of potentially enhanced benefits to anisometropic amblyopes from proposed new binocular therapies.

Comparison of amblyopia in schoolchildren in Ireland and Northern Ireland: a population-based observational cross-sectional analysis of a treatable childhood visual deficit

OBJECTIVES

This study reports the prevalence of persistent amblyopia (post-traditional treatment age) in schoolchildren in the Republic of Ireland (henceforth Ireland) and Northern Ireland (NI), UK; populations with broadly similar refractive and genetic profiles but different eye-care systems.

DESIGN

This is a population-based observational study of amblyopia and refractive error.

SETTING

Recruitment and testing in primary and post-primary schools in Ireland and NI.

PARTICIPANTS

Two groups identified through random cluster sampling to represent the underlying population; Ireland 898 participants (12-13 years old) and NI 723 participants (295 aged 9-10 years old, 428 aged 15-16 years old).

MAIN OUTCOME MEASURES

Monocular logMAR visual acuity (presenting and pinhole), refractive error (cycloplegic autorefraction), ocular alignment (cover test) and history of previous eye care. These metrics were used to determine prevalence and type of amblyopia and treatment histories.

RESULTS

Children examined in NI between 2009 and 2011 had a significantly lower amblyopia prevalence than children examined in Ireland between 2016 and 2018 (two-sample test of proportions, p<0.001). Using a criteria of pinhole acuity 0.2logMAR (6/9.5 Snellen) plus an amblyogenic factor, 4 of 295 participants aged 9-10 years old (1.3%, 95% CIs 0.4 to 3.6) and 3 of 428 participants aged 15-16 years old (0.7%, 95%CIs 0.2 to 2.2) were identified in NI. The corresponding numbers in Ireland were 40 of 898 participants aged 12-13 years old (4.5%, 95% CI 3.2 to 6.1). In NI strabismic amblyopia was the most prevalent type of persistent amblyopia, whereas anisometropic was predominant in Ireland. In Ireland, amblyopia was associated with socioeconomic disadvantage (OR=2.2, 95%CIs 1.4 to 3.6, p=0.002) and poor spectacle compliance (OR 2.5, 95% CIs 2.0 to 3.2, p<0.001).

CONCLUSIONS

Amblyopia prevalence persisting beyond traditional treatment ages was significantly lower among NI children compared with Ireland. Uncorrected anisometropia, compliance with spectacle wear and socioeconomic disadvantage were contributing factors in Ireland. Children without obvious visible eye defects were less likely to access eye care in Ireland, resulting in missed opportunities for intervention where necessary.