Prevalence of refractive error, presbyopia and spectacle coverage in Kahama District, Tanzania: a rapid assessment of refractive error

Background In Tanzania, the prevalence of refractive error and presbyopia have not been comprehensively assessed, limiting appropriate planning and implementation of delivery of vision care. This study sought to determine the prevalence of refractive error and presbyopia, spectacle coverage and the barriers to uptake of refractive services in people aged 15 years and older in the Kahama district of Tanzania. Methods A cross-sectional community-based survey was conducted using 54 randomly selected clusters. Respondents 15 years and older were interviewed and underwent standardised clinical eye examinations. Uncorrected refractive error (URE) was defined as presenting vision worse than 6/12 that could be corrected to better than 6/12 using a pinhole. Spectacle coverage was defined as the proportion of need that was met (those that improved from unaided vision with their own spectacle correction). Results A total of 3,230 subjects (99.75 per cent of 3,240 eligible) participated in the study with 57.2 per cent males and the median age of participants was 35 years (inter-quartile range, 24 to 49). The prevalence of visual impairment was 10.4 per cent (95% CI 9.4 to 11.4) and was lower in those who had completed their primary school education (odds ratio (OR) 0.54, 95% CI: 0.40 to 0.72) and highest in subjects 40 years and older (OR 3.17, 95% CI: 2.14 to 4.70) and farmers (OR 8.57 95% CI: 2.27 to 32.43). Refractive error prevalence was 7.5 per cent (95% CI: 6.65 to 8.54) and this was highest in participants over 40 years (OR 1.60, 95% CI: 1.14 to 2.25) and in students (OR 3.64, 95% CI: 1.35 to 9.86). Prevalence of presbyopia was 46.5 per cent (773/1,663, 95% CI: 44.34 to 48.75). Spectacle coverage for refractive error and presbyopia was 1.69% (95% CI: 0 to 3.29) and 0.42% (95% CI: 0 to 1.26), respectively. Conclusion Uncorrected refractive error is a public health challenge in the Kahama district and sustainable service delivery and health promotion efforts are needed.