A comparative clinical survey of the prevalence of refractive errors and eye diseases in urban and rural school children

Objective: To assess the prevalence of refractive error and common ocular diseases in school-aged children in urban and rural populations in and around Hyderabad, India. Design: Population-based, cross-sectional study. Participants: A total of 33 14 school children, 1789 from urban areas and 1525 from rural areas. Methods: The examination included visual acuity measurements, retinoscopy and autorefraction under cycloplegia, examination of the anterior segment and external eye, and ocular motility evaluation. Results: In the urban group the prevalence of uncorrected presenting and best-corrected visual impairment (<= 20/40 in the better eye) was 9.8%, which dropped to 7.1% with presenting vision and was further reduced to 1.1% with best-corrected visual acuity. Uncorrected visual acuity in the rural group was 6.6%, which dropped to 3.3% with presenting vision and was further reduced to 2.5% with best-corrected visual acuity. The prevalence of refractive error was greater (25.2%) in the urban than the rural group (8%). Myopia measured with autorefraction was observed in 51.4% of urban children and 16.7% in rural children. Increased literacy rate, duration of study hours, and older age of the child were found to have contributed more to the prevalence of myopia in the urban group. Hyperopia with autorefraction was found to be 3.3% in the urban and 3.1% in the rural group. Hyperopia was associated with younger age in the study group. Trachoma was the leading cause of ocular morbidity in the rural group (3.5%) compared with the urban group (0.16%). Night blindness was reported in 3.2% of children in the rural group and 0.33% in the urban group. Vitamin A deficiency, low socio-economic status, and poor personal and environmental hygienic practice were found to have a positive correlation with ocular morbidity among rural group children. Conclusions: Provision of health education, periodic visual screening programs, and primary eye care by trained health care personnel in the elementary schools will prevent the prevalence of refractive errors and common ocular diseases in school children.