ABSTRACT
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.
ABSTRACT
Introducción: la evaluación de la visión de un infante se determina empleandolas cartas de agudeza visual, aunque se les conoce comúnmente con el nombre de optotipos, de las cuales la más frecuentemente empleada es la Snellen.Objetivo: determinar la reproducibilidad inter observadores y la concordancia dedos test que miden la agudeza visual en infantes escolares. Materiales y métodos: se evaluaron 61 niños (122 ojos) visualmente sanos conedades entre los 6 a10 años de un colegio de la ciudad de Pereira. La agudeza visual (AV) fue valorada con una carta Snellen de letras y con una carta LEA por parte de dos evaluadores independientemente. Resultados: la AV promedio fue de 0.0 unidades del logaritmo del mínimo ángulo de resolución (logMAR) (20/20) y la diferencia media entre los test fue -0.05 (IC95 porciento-0.064 a -0.037) logMAR; el coeficiente de reproducibilidad (COR) fue mejor parala carta LEA que Snellen (±0.08 y 0.12) superior a lo reportado en estudios previos (±0.15).Conclusión: la concordancia con el coeficiente de correlación intraclase mostró ser moderada (0.493) y los límites de acuerdo mostraron que había una mayor variación entre las mediciones para cuando la AV era más alta. Las cartas LEA y Snellen mostraron una buena reproducibilidad, no obstante la variabilidad en las mediciones entre ellas indica que no son pruebas intercambiables.
Introduction: the evaluation of the vision of an infant is determined using the visual acuity charts, although they are commonly referred to as the optotypes, of which the most frequently used is the Snellen.Objetive: to determinate test retest reliability and the agreement of two tests used to assess elementary school children visual acuity. Methods: we evaluated 61 visual healthy children (122 eyes) ages 7 through 10enrolled in elementary school of Pereira. Visual acuity (VA) was measured with Snellen letters chart and LEA symbols chart by two evaluators.Results: the average of VA was 0.0 of logarithm of minimum angle of resolution(logMAR), the mean difference between the test was -0.05 (CI95% -0.064 to -0.037) logMAR; the coefficient of repeatability (COR) was better for LEA symbols and Snellen chart (±0.08 and 0.12) than those reported in previous papers (±0.15). Conclusion: the coefficient correlation Intraclass (CCI) has indicated a moderateconcordance (0.493) and the 95% limits of agreement showed a wider difference between the both charts measurements as while visual acuity was better. LEA symbols and Snellen chart have showed good test retest reliability, although the variability between both measurements indicates that they are not interchangeabletest.