Perceptual learning in children with visual impairment improves near visual acuity.
OBJECTIVE
This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment.


METHODS
Participants were 45 children with visual impairment and 29 children with normal vision. Children with visual impairment were divided into three groups: a magnifier group (n = 12), a crowded perceptual learning group (n = 18), and an uncrowded perceptual learning group (n = 15). Children with normal vision also were divided in three groups, but were measured only at baseline. Dependent variables were single near visual acuity (NVA), crowded NVA, LH line 50% crowding NVA, number of trials, accuracy, performance time, amount of small errors, and amount of large errors. Children with visual impairment trained during six weeks, two times per week, for 30 minutes (12 training sessions).


RESULTS
After training, children showed significant improvement of NVA in addition to specific improvements on the training task. The crowded perceptual learning group showed the largest acuity improvements (1.7 logMAR lines on the crowded chart, P < 0.001). Only the children in the crowded perceptual learning group showed improvements on all NVA charts.


CONCLUSIONS
Children with visual impairment benefit from perceptual training. While task-specific improvements were observed in all training groups, transfer to crowded NVA was largest in the crowded perceptual learning group. To our knowledge, this is the first study to provide evidence for the improvement of NVA by perceptual learning in children with visual impairment. (http://www.trialregister.nl number, NTR2537.).
Bartiméus, Institute for the Visually Impaired, Zeist, The Netherlands.
Bianca
B
Huurneman
F Nienke
FN
Boonstra
Ralf F A
RF
Cox
Ger
G
van Rens
Antonius H N
AH
Cillessen
D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D004193:Discrimination Learning / Q000502:physiology*; D005260:Female; D005584:Fovea Centralis / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*
children's vision; near visual acuity; perceptual learning; visual impairment