The assistance of electronic visual aids with perceptual learning for the improvement in visual acuity in visually impaired children

PURPOSE

To investigate the effect of electronic visual aids (EVA) combined with perceptual learning (PL) for the improvement in visual acuity for moderate to severe visually impaired and blind children.

METHODS

Twenty-eight 6- to 14-year-old visually impaired children (19 boys and 9 girls) were divided into two groups: PL under the assistance of EVA (Group A, 14 children) and simple PL without EVA (Group B, 14 children). The content of PL was to search the inversed "E" in the crowding strings and connected with lines, 30 minutes a day for 6 months. EVA can provide 5-10 times magnification on the 4.3-inch screen. Uncorrected distance visual acuity (UCVA), best-corrected visual acuity (BCVA), near visual acuity (NVA) and refractive error were evaluated before and 3 and 6 months after training.

RESULTS

Baseline UCVA, BCVA or NVA was comparable between the two groups. Three months after training, UCVA, BCVA and NVA improved significantly in Group A (p < 0.05). At the end of training, UCVA and BCVA continued progressing in Group A compared to 3 months (p = 0.01, 0.02), but visual acuity did not show significant improvement in Group B during the same time, except that UCVA improved at the first follow-up. Refractive error had no significant change post-training in both groups.

CONCLUSIONS

Visually impaired children can benefit more from the combination of PL with EVA than simple PL, and the improvement in visual acuity accompanied no significant myopic shift. It may provide a new method of treatment and rehabilitation in visually impaired children.

[Closed-circuit television systems : Current importance and tips on adaptation and prescription]

Closed-circuit television systems (CCTVs) have become an indispensable tool in rehabilitating low vision patients. Compared to optical visual aids, apart from providing maximum magnification these devices have the additional advantage of improved contrast sensitivity and an enlarged field of view. They are often the only visual aid enabling patients to regain reading ability. Our data reflect a decrease in the number of prescriptions caused by improved counseling of low-vision patients. Any prescription of reading aids must be preceded by comprehensive testing and counseling. More recent developments, such as electronic magnifiers are becoming increasingly more important but they are no substitute for CCTV.