Home-based visual perceptual learning improves contrast sensitivity in Parkinson's disease: a proof-of-concept study

To assess whether visual perceptual learning (VPL) enhances contrast sensitivity function (CSF) in Parkinson's disease (PD); as a secondary exploratory aim, to describe whether the two protocols targeting different spatial frequency ranges produced differential effects.

Seventeen patients with PD were randomized to two VPL protocols using dichoptic Gabor patch video-games for 30 minutes/day, six days/week, over 8 weeks. The M-H group trained at 8-16 cpd and the L-M group at 0.5-2 cpd. CSF was measured at baseline, 2, 4, and 8 weeks. BCVA and VIPD-Q were assessed at baseline and 8 weeks.

Significant progressive improvements in CSF were observed across all spatial frequencies and in the area under the log CSF curve from 1 month of training (p<0.001). VIPD-Q scores improved significantly in both groups (p=0.02 and p=0.008, respectively).

Home based VPL was associated with significant improvements in CSF in PD; however, the absence of a control group means that these findings remain preliminary.