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

Disparities in Amblyopia Treatment Outcomes: The Impact of Sociodemographic Factors, Treatment Compliance, and Age of Diagnosis

PURPOSE

To identify clinical and sociodemographic factors associated with disparities in amblyopia treatment outcomes.

DESIGN

Retrospective chart review.

PARTICIPANTS

Children ≤ 8 years of age diagnosed and treated for unilateral refractive or strabismic amblyopia at our institution from 2012 to 2022.

METHODS

Children with amblyopia were categorized by outcome: resolved amblyopia (< 0.2 logarithm of the minimum angle of resolution [logMAR] interocular difference [IOD] in visual acuity [VA] or no fixation preference in nonverbal patients) or persistent amblyopia. Demographic and clinical data were recorded from the medical record. Zip codes were used to calculate Childhood Opportunity Index (COI) scores, estimated annual household income, and distance to hospital.

MAIN OUTCOME MEASURES

Sociodemographic and clinical factors were compared between children with resolved and persistent amblyopia. Factors significant at P < 0.10 on univariate analysis were included in a multivariable regression model.

RESULTS

A total of 168 patients met inclusion criteria, and 131 patients (78%) had resolved amblyopia. Demographic factors associated with resolution of amblyopia were younger age at diagnosis (3.3 ± 1.7 years vs. 4.5 ± 1.9 years; P = 0.0009), English as the primary language (79.4% vs. 62.2%; P = 0.04), higher estimated annual income ($83 315.93 ± $29 276.64 vs. $71 623.00 ± $26 842.56; P = 0.03), higher COI scores (50.9 ± 27.3 vs. 40.0 ± 26.4; P = 0.03), and living farther from our institution (28.6 ± 37.6 miles vs. 14.9 ± 12.7 miles; P = 0.003). Patients with resolved amblyopia also had higher rates of treatment compliance (83.2% ± 25.0% vs. 75.6% ± 24.4%; P = 0.009) and shorter delays in follow-up (40.1 ± 76.8 days vs. 61.1 ± 90.4 days; P = 0.02). Amblyopia persistence was borderline associated with governmental insurance and higher presenting IOD in VA (both P = 0.06). On multivariate analysis, only younger age at amblyopia diagnosis (P = 0.0010) remained significantly associated with amblyopia resolution.

CONCLUSIONS

Our findings suggest that disparities in amblyopia outcomes are related to differences in age at diagnosis. Interventions to lower the age at which amblyopia is diagnosed, such as programs to improve vision screening rates and access to pediatric eye care in at-risk groups, may directly address inequities in rates of amblyopia resolution.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Using electronic medical record data to establish and monitor the distribution of refractive errors. JOURNAL OF OPTOMETRY 2022;15 Suppl 1:S32-S42. [PMID: 36220741 PMCID: PMC9732486 DOI: 10.1016/j.optom.2022.09.001]

OBJECTIVE

To establish the baseline distribution of refractive errors and associated factors amongst a population that attended primary care optometry clinics.

DESIGN

Retrospective cross sectional cohort study of electronic medical records (EMR).

METHODS

Electronic medical record data was extracted from forty optometry clinics, representing a mix of urban and rural areas in Ireland. The analysis was confined to demographic and clinical data gathered over a sixty-month period between 2015 and 2019. Distribution rates were calculated using the absolute and relative frequencies of refractive error in the dataset, stratified for age and gender using the following definitions: high myopia ≤ -6.00 D, myopia ≤ -0.50 D, hyperopia ≥ +0.50 D, astigmatism ≤ -0.75 DC and anisometropia ≥ 1.00 D. Visual acuity data was used to explore vision impairment rates in the population. Further analysis was carried out on a gender and age-adjusted subset of the EMR data, to match the proportion of patients in each age grouping to the population distribution in the most recent (2016) Irish census.

RESULTS

153,598 clinic records were eligible for analysis. Refractive errors ranged from -26.00 to +18.50 D. Myopia was present in 32.7%, of which high myopia represented 2.4%, hyperopia in 40.1%, astigmatism in 38.3% and anisometropia in 13.4% of participants. The clinic distribution of hyperopia, astigmatism and anisometropia peaked in older age groups, whilst the myopia burden was highest amongst people in their twenties. A higher proportion of females were myopic, whilst a higher proportion of males were hyperopic and astigmatic. Vision impairment (LogMAR > 0.3) was present in 2.4% of participants. In the gender and age- adjusted distribution model, myopia was the most common refractive state, affecting 38.8% of patients.

CONCLUSION

Although EMR data is not representative of the population as a whole, it is likely to provide a reasonable representation of the distribution of clinically significant (symptomatic) refractive errors. In the absence of any ongoing traditional epidemiological studies of refractive error in Ireland, this study establishes, for the first time, the distribution of refractive errors observed in clinical practice settings. This will serve as a baseline for future temporal trend analysis of the changing pattern of the distribution of refractive error in EMR data. This methodology could be deployed as a useful epidemiological resource in similar settings where primary eyecare coverage for the management of refractive error is well established.

The Global Prevalence of Amblyopia in Children: A Systematic Review and Meta-Analysis

Epidemiological data about the prevalence of amblyopia around the world vary widely among regions and periods. This meta-analysis aimed to determine the global prevalence of amblyopia in children. PubMed, Embase, and the Cochrane Library were searched for prevalence studies published up to 5 November 2021. The outcome was the prevalence of amblyopia, analyzed as pooled estimates with 95% confidence intervals (CI). A total of 97 studies were included, including 4,645,274 children and 7,706 patients with amblyopia. The overall worldwide pooled prevalence of amblyopia was 1.36% (95%CI: 1.27-1.46%). The prevalence of amblyopia was higher in males (1.40%, 95%CI: 1.10-1.70%) than in females (1.24%, 95%CI: 0.94-1.54%) (OR = 0.885, 95%CI: 0.795-0.985, P = 0.025). The results of the meta-regression analysis showed that there were no significant associations between the prevalence of amblyopia and geographical area, publication year, age, sample size, and whether it was carried out in a developed or developing country (all P > 0.05). Begg's test (P = 0.065) and Egger's test (P < 0.001) showed that there was a significant publication bias in the prevalence of amblyopia. In conclusion, amblyopia is a significant vision problem worldwide, and public health strategies of early screening, treatment, and management are important.

Treatment Outcome of Occlusion for Unilateral Amblyopia in Saudi Children 6-12 Years Old

PURPOSE

The purpose of this study was to estimate the rate and review determinants of successful therapy for unilateral amblyopia in children.

METHODS

This prospective cohort consisted of Saudi children aged 6-12 who received amblyopia therapy between 2020 and 2022. Best-corrected visual acuity (BCVA) in the amblyopic eye improved to reach the BCVA of the fellow eye at follow-up visits, or BCVA in the amblyopic eye improved and remained stable over three follow-up visits. Demographic and ocular characteristics were associated with the outcome.

RESULTS

In 30 children, the median BCVA at presentation and the last follow-up was 0.8 logMAR (interquartile range [IQR]: 0.6; 1.0) and 0.45 logMAR (IQR: 0.3; 0.6), respectively. The success rate of amblyopia therapy was 80% (95% confidence interval: 65.7; 94.3). It was 100%, 76.5%, and 77.8% in eyes with anisometropic, strabismic, and mixed types of amblyopia, respectively. Amblyopia grade (P = 0.177), type of amblyopia (P = 0.96), and spectacles as therapy in the past (P = 0.09) were not significantly associated with the successful out. The duration of follow-up was significantly longer in those with unsuccessful outcomes (P = 0.05). Excellent compliance for occlusion was observed in 62.5% of children with successful outcomes. In 14 (46.7%) children, BCVA was ≤0.3 logMAR BCVA at the last follow-up. Two-line improvement in amblyopic eyes was in 26 (86.7%) children at the last follow-up compared to BCVA at presentation.

CONCLUSION

Occlusion therapy complemented using glasses in older children also significantly improved visual recovery in amblyopic eyes.

Association of multimedia teaching with myopia: A national study of school children

AIM

The aim of this study was to determine whether students' exposure to digitally projected, multimedia teaching material under naturally varying classroom lighting conditions is associated with myopia risk and severity.

DESIGN

A population-based, cross-sectional study in 2012 of children in grades 4-6 across 87 schools in Taiwan.

METHODS

Students (N = 3,686) reported demographic information, outdoor time, physical activity and near work. Parents provided their myopia status. Student-reported multimedia teaching frequency and classroom lighting levels were confirmed with direct observation. School nurses conducted vision screening and ophthalmologist referral. Myopia status and severity were measured by spherical equivalent refraction; SE ≤-0.5 dioptres was coded as myopic. Binary logistic and tobit regression were used to estimate the contributions of classroom multimedia exposure and lighting to myopia risk and severity controlling for risk factors.

RESULTS/FINDINGS

Age, parental myopia and hours of near work increased the odds of myopia and predicted greater severity. Physical activity and outdoor time predicted lower risk and severity. Multimedia exposure in relatively bright classrooms was associated with greater odds of myopia. Classroom lighting levels during multimedia teaching were inversely related to severity; exposure frequency was unrelated.

CONCLUSIONS

Multimedia exposure under brighter classroom conditions may contribute to the myopia incidence in schoolchildren.

IMPACT

Teaching with digital projection technology is increasingly prevalent. This may increase children's odds of developing myopia, which has far-reaching and lifelong deleterious effects. School nurses should raise awareness of and promote strategies that reduce this risk, including working with children, parents, school personnel and system leaders to adopt eye-healthy behaviours, practices and policies.