Prevalence of refractive errors in children in India: a systematic review

Methodological quality of the review: Medium confidence

Author: Sethu Sheeladevi, Bharani Seelam, Phanindra B Nukella, Aditi Modi, Rahul Ali, Lisa Keay

Region: India

Sector: Refractive error

Subsector: Prevalence of refractive errors

Equity focus: No

Study population: Children

Type of program: Community and school based

Review type: Other review

Quantitative synthesis method: Systematic review

Qualitative synthesis method: Not applicable

Background: Uncorrected refractive error is the most common cause of visual impairment around the world, and in children uncorrected refractive error and its consequences have a profound effect on their overall development, most importantly on educational and psychosocial development. In India, varied prevalence rates of myopia and hyperopia have been reported in children. It is recommended to screen children for early detection and intervention to provide them with the best opportunities to learn and develop. Region-specific prevalence estimates are necessary for policy decisions and evidence-based allocation of resources. However, cost and logistics limits make population-based studies from each region prohibitive and there are no systematic reviews on the question of prevalence of refractive error in children.

Objectives: The objective of this study was to estimate population- and school-based prevalence of refractive errors among children ≤ 15 years of age in India.

Main findings: Four population-based studies and eight school-based studies were included. The overall prevalence of refractive error per 100 children was 8.0 (CI: 7.4-8.1) and in schools it was 10.8 (CI: 10.5-11.2). The population-based prevalence of myopia, hyperopia (≥ +2.00 D) and astigmatism was 5.3%, 4.0% and 5.4%, respectively. Combined refractive error and myopia alone were higher in urban areas compared to rural areas (odds ratio [OR]: 2.27 [CI: 2.09-2.45]) and (OR: 2.12 [CI: 1.79-2.50]), respectively. The prevalence of combined refractive errors, myopia and hyperopia was higher in urban schools compared to schools in rural areas (OR: 4.9 [CI: 4.46-5.507], OR: 3.4 [CI: 3.03-3.92]) and OR: 14.1 [CI: 6-18.9]), respectively. The prevalence of combined refractive errors and myopia alone in schools was higher among girls than boys (OR: 1.2 [CI: 1.1-1.3] and OR: 1.1 [CI: 1.1-1.2]), respectively. However, hyperopia was more prevalent among boys than girls in schools (OR: 2.1 [CI: 1.8-2.4]).

Methodology: All epidemiological studies that reported prevalence of any refractive errors from an Indian population were considered for full text review.

OVID, Embase, EbscoHost and the Cochrane Library databases were searched using a strategy with terms based on medical subject headings used in the title and abstract. A manual search was also conducted – based on the reference lists of the eligible articles and reviews – for any additional articles. The systematic review met the criteria outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 guidelines. Two independent reviewers (SS, BS) completed all the first three steps and consensus was achieved through discussion in case of any discrepancies at any stage. The methodological quality of the eligible studies was assessed using the checklist developed by Munn et al. Data was extracted on the study year, design, sampling technique, screening tools, cycloplegia, screening personnel, location (urban or rural), total sample size, number of children with refractive error and number of children with different types of refractive error. OpenMeta [Analyst] – an open-source, cross-platform software for advanced meta-analysis (http://www.cebm.brown.edu/openmeta/) – was used to calculate the pooled estimate of refractive errors in children, which is the primary aim of this review. Cochran Q statistic testing was undertaken for heterogeneity across studies.

Applicability/external validity: This review is specific to India’s population, moreover, data included for analysis is out of date. The variation in refractive error definition, particularly in reporting hyperopia, contributed to the wide range of estimated prevalence. Few school-based studies considered in this review included relatively low amounts of refractive error; for example, +0.50 D, which is not clinically significant for spectacle correction in most children.

Geographic focus:

Summary of quality assessment:

Medium confidence was attributed to the conclusions about the effects of this review. Authors did not conduct thorough searches of the literature to ensure that all relevant studies were identified.