Purpose: To compare the efficacy of Lea symbols (LS) chart and Sheridan Gardiner (SG) chart for vision screening among preschool children, in a semi-urban district of South India.
Methods: Vision screening was conducted among 260 preschool children aged 3-5 years in cluster sampled kindergartens using LS chart and SG chart. Pass/fail scores and time taken for visual acuity (VA) estimation were compared. VA scores and time taken were compared using unpaired t-test. Sensitivity, specificity, and positive and negative predictive values were compared between the charts.
Results: There was a significant difference between LS and SG charts in the VA score in both the eyes (P = 0.04). LS showed 76.09% pass score and 23.90% fail score, whereas SG showed 87.65% pass score and 12.35% fail score with a cutoff value of > 0.3 log MAR. Time for screening using LS was higher, when compared to SG, both for the right eyes (P < 0.001) and the left eyes (P < 0.001). The sensitivity of the LS was 94.74% (95% confidence interval [CI]: 70.13%-81.06%) and that of SG was 52.63% (95% CI: 45.29%-59.8%). The specificity of LS was 66.67% (95% CI: 90.26%-97.30%) and SG was 83.33% (95% CI: 70.12%-91.30%).
Conclusion: LS chart showed better sensitivity and negative predictive value when compared to SG chart. However, SG chart showed better specificity and positive predictive value, and screening was less time-consuming. Considering the high sensitivity and negative predictive value, LS is the preferred tool, when compared to SG chart in preschool vision screening in our population.
Keywords: Lea symbol Chart; Sheridan Gardiner chart; preschool vision screening.