Prevalence of refractive errors in Nepalese children and adults: a systematic review with meta-analysis

Country-specific estimates of the prevalence of refractive errors are important to formulate national eye health policies for refractive care services.

The purpose of this study was to systematically synthesise available literature and estimate the prevalence of refractive errors in the Nepalese population.

PubMed, Scopus, and Web of Science databases were systematically searched for articles on refractive errors and presbyopia published in English language until 27 September 2022. Population and school-based quantitative, cross-sectional prevalence studies and Rapid Assessment of Avoidable Blindness survey repository data were included. The quality of the included studies was assessed using the Newcastle Ottawa scale adapted for cross-sectional studies. Data extraction was performed with consensus among the reviewers. Meta-analysis of the prevalence was performed using the Random effects model to estimate the pooled proportions.

A total of 38 studies with 101 701 participants were included: 18 studies in children (n = 31 596) and 20 in adults (n = 70 105). In children, the estimated pooled prevalence of overall refractive errors was 8.4% (95% CI: 4.8 to 12.9) with myopia, hypermetropia and astigmatism prevalent in 7.1% (95% CI: 3.7 to 11.4), 1.0% (95% CI: 0.7 to 1.3) and 2.2% (95% CI: 0.9 to 3.9), respectively. In adults, the prevalence of refractive errors, uncorrected refractive errors, and uncorrected presbyopia were 11.2% (95% CI: 8.0 to 14.9), 7.3% (95% CI: 5.4 to 9.5) and 78.9% (95% CI: 69.1 to 87.3), respectively.

The pooled prevalence of refractive errors is relatively low while uncorrected refractive errors and presbyopia are high in Nepalese population suggesting a need for better access to refractive care services in the country. The paucity of quality evidence on prevalence of refractive errors, particularly in children, indicates a need for a well-designed population-based study to accurately estimate the current prevalence of refractive errors.