Test-Retest Reliability of the Lea Symbols Chart in Preschool Children Aged 42−78 Months

Objective: To evaluate the repeatability of the Lea Symbols chart in vision examinations of preschool children. Methods: In this cross-sectional study, we included 250 children aged 42 through 78 months (61.9±10.3) from April to May 2017. All children completed comprehensive ophthalmological examinations and monocular assessment of visual acuity was performed in both eyes with the Lea Symbols chart. All visual acuity scores are presented in LogMAR units. Bland-Altman analysis, weighted Kappa test and correlation analysis were used to measure the reliability of repeated measurements between the two measurements. Results: The visual acuity (LogMAR) difference between test and retest thresholds was between ±0.10 in 94.3% of eyes. Correlation between test and retest thresholds was 0.753 (P<0.001). The mean difference in visual acuity (LogMAR) between test and retest was 0.014 in 139 preschool children without refractive errors. A significant relationship was found between age and visual acuity in 139 preschool children without refractive errors (rfirst=-0.335, P<0.001; rsecond=-0.424, P<0.001). Repeatability was not associated with gender (P=0.197). Conclusions: The Lea Symbols chart provides a repeatable measure of visual acuity in children 42 months and older. It is recommended for the clinical examination of children. Key words: Lea Symbols chart; preschool children; visual acuity; repeatability