Study of uncorrected refractory error, cataract and selected diseases of eye in urban and rural area near Chennai, Tamil Nadu

Background: Uncorrected refractory error and cataract are leading causes of preventable blindness in India. Objectives: To estimate prevalence and risk factors associated with uncorrected refractory error, cataract and selected eye diseases in urban and rural area near Chennai, Tamil Nadu. Methods: The present cross-sectional study was conducted in urban and rural areas near Chennai during May–August 2009. EPI 30-cluster sampling method was used and individuals in age group 5–70 years were selected with 450 subjects in both areas. Detail ophthalmic examination was done and socio-economic history for risk factors was obtained by trained interviewer. Data was analysed using SPSS version 15.0 software. To compare data sets chi-square test was used and Odds ratios calculated to assess association of risk factor. Results: 33.3% of the rural population had uncorrected refractory error as compared to 22.2% urban population (p<0.001); 24.2% rural population were having cataract compared to 13.1% urban population (p<0.001). Prevalence of pterygium and external hordeolum were 3% and 1% among total study population. Prevalence of internal hordeolum, corneal opacity and blepharitis were less than 1%. Subjects residing in rural area with low standard of living and using wood or cow-dung as cooking fuel were at significant higher risk of developing cataract (OR:2.43 and 2.88 respectively). They were also at significant higher risk of having refractory error (OR: 2.35 for low standard of living and 2.08 for wood or cow-dung as cooking fuel). Conclusion: Prevalence of uncorrected refractory error and cataract was high especially in rural area in the present study.