Abstract
Purpose :
Perceptual learning (PL) can improve a range of visual functions and near visual acuity (NVA) in visually impaired children, it is unknown whether or not the combination of visual aids (VA) and PL willl bring additional benefits. This prospective and controlled study investigated the effect of VA and PL in the improvement of visual acuity in low vision children.
Methods :
Twenty-eight low vision, nystagmus children (19 male and 9 female) were included in the study, aged from 6 to 13 years old, and were divided into 2 groups, PL with electronic VA (PL group, 14 children, mean BCVA was 1.24±0.37logMAR) and simple visual training (Control group, 14 children, mean BCVA was 1.07±0.37logMAR). Children in the PL group searched inversed “E” in crowded word strings with VA 30 minutes per day; children in the Control group received flashing light stimulation 30 minutes per day. We measured the uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BCVA), NVA, reading speed with and without VA, distance of reading and reading time duration, and evaluated quality of life using LV Prasad-Functional Vision Questionnaire (LVP-FVQ) before and 3 and 6 months after training. Student’s t-test, paired Student’s t-test and Mann-Whitney rank-sum test were used for statistical analysis.
Results :
Before treatment, age, gender ratio, primary UDVA, BCVA and NVA were comparable between the two groups. After six months, UDVA and NVA in the PL group was better than in the Control group(UDVA: t=-3.033, p=0.004; NVA: t=-2.696, p=0.01), and UDVA, BCVA and NVA in PL were better at six months than pre-training (UDVA: t=5.127, p<0.001; BCVA: t=3.504, p=0.003; NVA: t=3.361, p=0.004). While in the Control group, there was no significant difference of UDVA, BCVA and NVA between pre and 3 months later and pre and 6 months later. Furthermore, the reading speed in the PL group was greater at 6 months than pre-training, with or without VA (with VA: t=-3.621, p=0.008; without VA: t=-2.686, p=0.031). The distance of reading, reading time duration and the score of LVP-FVQ was not signficantly different between pre- and post-training in the PL group.
Conclusions :
Perceptual learning with visual aids can improve UDVA, NVA and reading speed of children with visual impairment. The effect of the training on the quality of life in low vision children needs further research.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.