Prevalence and patterns of refractive error among adults in Sagamu, South-West Nigeria

Abstract

Background: The study was part of community-based research towards strengthening the provision of optical services within a local governmental area in Nigeria.

Aim: To describe the prevalence of refractive errors in the southwestern Nigerian adult population.

Setting: Adults of age 30 years and above who were regular residents of the local governmental area.

Methods: A multistage stratified random cluster sampling method was used to select the subjects. The sampling unit was the different households. A random sample of them were refracted and then refractive errors were analysed. Analyses excluded participants with history of cataract surgery. Associations with myopia (−0.50 dioptres [D] or more) and hyperopia (≥ 0.50 D) were evaluated in logistic regression analyses.

Results: The prevalence of refractive error in the study sample was 33.8% (95% confidence level [CI]: 27.1–34.4) using study participants with < 6/9 presenting visual acuity but improvement by at least a line with pin hole. The prevalence of hyperopia was 46.9% and higher in women (51.8%), while that of myopia was 21.9% but higher in men (25.0%). The prevalence of hyperopia increased from 29% for 40–49 years of age to 65% for 50–59 years of age and tended to decline thereafter. Prevalence of myopia decreased from 17% in persons 40–49 years of age to 11% in those 50–59 years of age but increased after 60 years of age. A higher prevalence of myopia was positively associated (p < 0.05) with lifetime occupations requiring near work, nuclear opacities, posterior subcapsular opacities and glaucoma. Factors associated with hyperopia were the same as for myopia, except for occupation, and in the opposite direction.

Conclusion: The high prevalence of refractive errors strongly supports the need for an affordable and accessible optical service in the local government.