Purpose: To investigate distance and near contrast sensitivity (CS), as well as low-contrast visual acuities (LCVAs) at 5% and 2.5% contrasts across various eye diseases causing low vision, in children aged 5 to <16 years, and to study the repeatability of these measures. Methods: In total, 782 children (age, mean ± SD, 10.23 ± 2.75 years) with low vision, visual acuity between 0.3 and 1.3 logMAR, or visual field with mean deviation worse than 12 dB were recruited. CS was assessed with Pelli–Robson distance and near tests. Visual acuity and LCVAs at 5% and 2.5% contrast were assessed using LEA symbols. In 134 children, data were collected again in approximately 3 months for repeatability measures. Bland–Altman 95% limits of agreement (LoAs) were used to assess repeatability. Results: A wide range of CS (distance: 1.69 to 0.45 logCS, near 1.73 to 0.15 logCS) and LCVA (0.80 to 1.54 logMAR at 5% contrast and 0.94 to 1.58 logMAR at 2.5% contrast) were observed across 47 eye diseases in children with low vision. Repeated measures for CS and LCVA exhibited a large variation (LoA: distance CS = 0.44 logCS, near CS = 0.54 logCS, LCVA 5% = 0.38 logMAR, LCVA 2.5% = 0.42 logMAR) in children with low vision. Conclusions: CS and LCVA impairments vary across eye diseases in children. A difference of more than 0.45 logCS (three triplets) in CS or 0.4 logMAR (four lines) in LCVA during follow-up is considered clinically meaningful for children with low vision due to high test–retest variability.
Bagga et al. (Thu,) studied this question.