Refractive errors in an urban population in southern India: The Andhra Pradesh Eye Disease Study

PURPOSE. To assess the prevalence, distribution, and demographic associatio ns of refractive error in an urban population in southern India. METHODS. Two thousand five hundred twenty-two subjects of all ages, represe ntative of the Hyderabad population, were examined in the population-based Andhra Pradesh Eye Disease Study. Objective and subjective refraction was a ttempted on subjects >15 years of age with presenting distance and/or near visual acuity worse than 20/20 in either eye. Refraction under cycloplegia was attempted on all subjects less than or equal to 15 years of age. Spheri cal equivalent >0.50 D in the worse eye was considered as refractive error. Data on objective refraction under cycloplegia were analyzed for subjects less than or equal to 15 rears and on subjective refraction were analyzed f or subjects >15 years of age. RESULTS. Data on refractive error were available for 2,321 (92.0%) subjects . in subjects less than or equal to 15 years of age, age-gender-adjusted pr evalence of myopia was 4.44% (95% confidence interval [CI], 2.14%-6.75%), w hich was higher in those 10 to 15 years of age (odds ratio, 2.75; 95% CI, 1 .25-6.02), of hyperopia 59.37% (95% CI, 44.65%-74.09%), and of astigmatism 6.93% (95% CI, 4.90%-8.97%). In subjects >15 years of age, age-gender-adjus ted prevalence of myopia was 19.39% (95% CI, 16.54%-22.24%), bf hyperopia 9 .83% (35% CI, 6.21%-13.45%), and of astigmatism 12.94% (95% CI, 10.80%-15.0 7%). With multivariate analysis, myopia was significantly higher in subject s with Lens Opacity Classification System III nuclear cataract grade greate r than or equal to 3.5 (odds ratio, 9.19; 95% CI, 5.15-16.09), and in subje cts with education of class 11 or higher (odds ratio, 1.80; 95% CI, 1.18-2. 74); hyperopia was significantly higher in subjects greater than or equal t o 30 years of age compared with. those 16 to 29 years of age (odds ratio, 3 7.26; 95% CI, 11.84-117.19), in females (odds ratio, 1.86; 95% CI, 1.33-2.6 1), and in subjects belonging to middle and upper socioeconomic strata (odd s ratio, 2.10; 95% CI, 1.09-4.03); and astigmatism was significantly higher in subjects greater than or equal to 40 years of age (odds ratio, 3.00; 95 % CI, 2.23-4.03) and in those with education of college level or higher (od ds ratio, 1.73; 95% CI, 1.07-2.81). CONCLUSIONS. These population-based data on distribution and demographic as sociations of refractive error could enable planning of eye-care sen ices t o reduce visual impairment caused by refractive error. If these data are ex trapolated to the 255 million urban population of India, among those >15 ye ars of age an estimated 30 million people would have myopia, 15.2 million h yperopia, and 4.1 million astigmatism not concurrent with myopia or hyperop ia; in addition, based on refraction under cycloplegia, 4.4 million childre n would have myopia and 2.5 million astigmatism not concurrent with myopia or hyperopia.