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

Purpose: 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. Methods: 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. Results: 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). Conclusions: 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.