Sensitivity and specificity of teachers for vision screening among primary school children in South India

AIMS: This study aims to determine the sensitivity and specificity of vision screening by school teachers among primary school children. SETTINGS AND DESIGN: Prospective nonrandomized clinical trial. SUBJECTS AND METHODS: The study was carried in primary school children of Madurai, Tamil Nadu from April 2007 to October 2007. Sixty-five primary school teachers from 57 schools around Madurai, Tamil Nadu, India, underwent a half-day training programme at the hospital. Each teacher on return to the school screened around a hundred children using the tumbling E. All screened children were subsequently screened by a team from the hospital. The optometrists used tumbling E (Snellen's 20/30 and Early Treatment of Diabetic Retinopathy Study (ETDRS) 20/32) to check the vision of all children. Any child complaining of defective vision or noted to have defective vision on screening underwent a comprehensive ophthalmic evaluation. The sensitivity and specificity of teacher screening was assessed based on the data obtained. RESULTS: Screening was completed for 5150 children. The prevalence of vision <20/30 was 2.82%. Teacher screening was noted to have a sensitivity of 24.8% and a specificity of 98.65%. Tumbling E ETDRS screening by the optometrist had the highest sensitivity of 94.48% and specificity of 97.09%. CONCLUSIONS: Our study shows that vision screening by trained optometrists is a very useful tool to identify visual impairment in primary school children. Measures need to be taken to improve the sensitivity of teacher screening before recommending its generalized use.