Prevalence of refractive error in Nigerian children

Abstract

Refractive errors can have profound effects on children. Cost and logistics prohibit national population-based studies and global data do not accurately reflect the burden among Nigerian children. This systematic review and meta-analysis aim to provide pooled prevalence and pattern of refractive error in Nigerian children. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol for this study was pre-specified and registered on the International Prospective Register of Systematic Review (registration number ID: CRD42022303419). A systematic search of PubMed, EMBASE, Scopus, CINAHL Cochrane Library, African Journal Online, and African Index Medicus databases, was done for school-based, or population-based studies on refractive error prevalence in Nigerian children younger than 18 years of age or school children in pre-tertiary institutions. Quality-effect model was used to calculate weighted prevalence, odds ratio, and corresponding 95% confidence interval. Twenty-eight school-based studies including 34,866 children were identified. No population-based studies were found. The pooled prevalence of refractive error in Nigerian children was 5.9% (3.6-8.7%) and varied between regions and with the definition of refractive error used in the studies. The number of children needed to be screened to detect one case of refractive error was 15 (9-21). The odds of refractive error was higher in girls (odds ratio: 1.3 {1.1 to 1.5}), children >10 years (odds ratio: 1.7 {1.3 to 2.2}), and urban residents (odds ratio: 2.0 {1.6 to 2.5}). The high prevalence of refractive error in Nigerian children substantiates the value of screening school children for refractive error, particularly targeting urban and older children. Research is needed to refine case definitions and improve screening protocol. Population-based studies are needed to define the prevalence of refractive error in communities. The epidemiologic and methodological challenges in conducting prevalence reviews is discussed.