Validity of different screening tests for detecting visual impairment in 3 to 6 year old children

Background: Preschool vision screenings (PVS) are recommended for early detection and treatment of childhood visual disorders. At present, the vision screening protocols in childhood varies from country to country and even within countries Objective: To determine the sensitivity and specificity of different screening tests used for visual impairment detection in the 3 to 6 year old children Method: Ethical Committee approval and parental consent obtained. Each child was assessed with Lea symbol and E charts for vision, stereo acuity measurement with Randot preschool stereo test, photo refraction by Plus optix A09, cover tests, cycloplegic refraction and retinal evaluation. Visual impairment (VI) was defined as presenting visual acuity in better eye <6/12. Receiver Operating Characteristics Curve (ROC) was used for statistical analysis Results: A total of 200 eyes (100 participants) were analysed. 52% were males and 48% females.49.5% had visual impairment. The sensitivity and specificity of Lea symbol chart, Randot preschool and Plus optix A09 (spherical and cylindrical values) for detecting visual impairment were 91.8%, 56.2%, 51.8%,81.8% and specificity were 91.9%,83.3%,50%, 68% respectively. Conclusion: Lea symbol chart had high sensitivity to pick up visual impairment in 3 to 6 year old children.