Contrast Sensitivity and Low Contrast Visual Acuity in Children With Normal Visual Acuity

Abstract

To measure and report the distribution of distance and near contrast sensitivity (CS) and low contrast visual acuity (LCVA) at 5% and 2.5% contrast in children aged 5-15 years with normal visual acuity (VA). Prospective, cross-sectional study. Schools in Southern India. One thousand fifty-two children aged 5 to 15 years (mean age 10.61 ± 2.85 years) with a presenting visual acuity of 0.00 logMAR or better in both eyes and a stereo acuity of 40 seconds of arc or better were recruited from nine schools. Repeatability of contrast sensitivity and low contrast visual acuities were tested in 246 children. Pelli-Robson charts were used to measure the distance and near contrast sensitivity at 1 m and 40 cm, respectively. The low contrast visual acuity was recorded at 5% and 2.5% contrast using LEA Symbols at 3 m. Overall, the mean ± SD, (95% CI) monocular distance and near CS were 1.75 ± 0.11 (1.76-1.75) logCS and 1.72 ± 0.10 (1.73-1.71) logCS, respectively. The mean LCVA at 5% and 2.5% contrasts were 0.20 ± 0.10 (0.21-0.20) logMAR and 0.39 ± 0.11 (0.40-0.39) logMAR, respectively. Distance and near CS gradually improved till the ages of 11 and 13, respectively, and then plateaued. Similarly, LCVA at 5% and 2.5% contrasts gradually improved till age ten before plateauing. The Coefficient of Repeatability (CoR) for CS was ±0.02 logCS for distance, ±0.05 logCS for near, and ±0.01 logMAR for both LCVA contrasts. The study provides age-specific normative values for distance and near CS, and LCVA in a cohort of children aged 5-15 years. These results are important to understand the impact of ocular conditions on CS in children and have utility in clinical evaluations.