ABSTRACT
Background:There is a global epidemic of refractive error with myopia being the most prevalent cause of correctable visual impairment. However there is little data on refractive error in sub-Saharan Africa. This study assesses the prevalence and pattern of refractive errors (RE) in urban public high school students in Nairobi County, Kenya.Methods: This was a cross-section based survey of among1376 teenage high school students in Nairobi County, Kenya. Eleven out of 80 schools were selected and all the students in selected schools were invited to participate. All the students had their visual acuity taken using logMAR charts and those with a visual acuity of 6/12 or less in the better eye were invited for objective then subjective refraction. The data was analysed using SPSS 20.0. Chi-square test was used compare means and proportions.Results:The total participation rate was 84.8% (1376/1622). Of the 1376 students who participated 751 (54%) were boys and 639 (46%) were girls. The prevalence of refractive error was 15.5% (209/1348) with a preponderance of myopia at 14.4% [194/1348, OR= 0.7(95% CI= 0.4-0.9)], followed by astigmatism at 7.6% [103/1348, OR= 0.9, (95% CI= 0.6-1.3)] and lastly at 0.7% [10/1348, OR= 0.6 (95% CI=0.2-2.0)] hyperopia. Boys were less likely than girls to have both refractive error (OR= 0.7, 95% CI= 0.5-0.9) and myopia (O.R= 0.7, 95% C.I= 0.4-0.9).Congruous low myopia, i.e. occurring in both eyes (75.4%, 153/209) was the commonest form of refractive error among students with refractive error.Conclusions: There was a high prevalence of refractive error among teenagers attending high school in Nairobi Kenya with a predominance of myopia especially amongst girls.