Systematic review and meta-analysis of refractive errors in Ghana with emphasis on myopia

Refractive errors remain the leading cause of visual impairment globally, with myopia representing the most prevalent. In Ghana, reported prevalence estimates for refractive errors and myopia show considerable variability across studies, which complicates accurate quantification of their public burden and poses challenges for evidence-informed policy formulation and planning. The study aimed to estimate the prevalence of refractive errors in Ghana, with particular emphasis on myopia.

The systematic review followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and was prospectively registered with the Prospective Register of Systematic Reviews (PROSPERO; registration number CRD42022377958). A comprehensive and independent search of the literature was undertaken to identify peer-reviewed cross-sectional studies, using predefined Medical Subject Heading (MeSH) and relevant keyword subheadings across five electronic databases: PubMed, ProQuest, Scopus, Google Scholar, and Semantic Scholar. Pooled prevalence estimates with corresponding 95% confidence intervals (CIs) were calculated using an inverse-variance random-effects model, as substantial heterogeneity was anticipated and confirmed (I² ≥ 50%). Subgroup analyses were performed to report prevalence estimates stratified by refraction method, age group, study setting, and sex.

Twenty-four studies involving 19,331 participants were analysed. Pooled prevalence of total refractive error, myopia, hyperopia and astigmatism were 19.0% (95% CI: 16.0% - 22.1%), 7.1% (95% CI: 5.5%-8.6%), 4.4% (95% CI: 3.4%-5.4%) and 6.3% (95% CI: 4.8% - 7.9%) respectively. These varied according to method of refraction, age group, study setting and sex, with corresponding estimates of 19.0% (95%CI:16.0, 22.1), 20.3% (95%CI:12.0, 28.6), 19.0% (95%CI:16.0, 22.1), and 14.2% (95%CI: 11.4, 16.1) respectively. Subgroup analyses demonstrated significant variation in myopia prevalence, with higher estimates observed in non-cycloplegic studies at 7.9% (95% CI: 6.0-9.8), among adolescents at 22.4% (95% CI: 7.1-37.7), in school-based studies at 8.8% (95% CI: 6.7-10.8), and among females at 9.5% (95% CI: 5.9-13.1).

Prevalence of refractive errors, including myopia, in Ghana remain key public health concern, and vary substantially according to the refraction method employed, the age group studied, and the study setting. This heterogeneity underscores the influence of methodological and population-specific factors and provides an evidence base for informing context-specific and targeted eye-health interventions.