Causes of vision impairment and blindness among children in schools for the blind in South Indian States of Andhra Pradesh and Telangana

Purpose: To study the causes of severe vision impairment (SVI) and blindness among children in Andhra Pradesh (AP) and Telangana State (TS) in South India. Methods: A total of 299 children from 10 schools for the blind were examined between January and December 2017. The schools were chosen from 3 districts of AP (Guntur, Krishna and West Godavari) and 2 districts of TS (Adilabad and Mahabubnagar). The World Health Organization Prevention of Blindness' eye examination protocol for children with blindness or visual impairment (VI) was followed. Results: Based on presenting visual acuity (PVA), 248 children (82.9%) were blind, 16 children (5.3%) had SVI, 18 (6%) had moderate VI, and 17 (5.7%) were normal. The most common anatomical cause of blindness or SVI was whole globe anomaly (32%), followed by an abnormality in the retina and vitreous (26.6%). While whole globe anomalies were high both in AP (33.8%) and TS (21.6%), lens-related pathologies were higher in TS (29.7%) and retina-related abnormalities were higher in AP (29.3%). The most common cause was related to heredity (40.5%). Etiology was unknown in 33.5% of cases. Overall, 37.1% of the causes were avoidable. In AP, 33.4% were avoidable whereas in TS nearly 60% were avoidable. Conclusion: Whole globe anomaly constitutes a major cause of SVI and blindness, especially in AP. Lens-related pathologies were higher in TS. Nearly 40% of the causes were avoidable. Hence, robust screening methods and strategies must be established for timely intervention to reduce the burden on VI in children.