Alterations in chromatic contour perception in de novo parkinsonian patients

Recently abnormalities of chromatic visual perception were reported in treated patients with Parkinson's disease (PD). We studied 28 previously untreated Parkinsonian patients and 28 age- and sex-matched controls using a computer-aided method to determine the chromatic fusion time (CFT). CFT indicates the acuity of the perception of monochromatic contours. Patients with PD have a shortened CFT especially for the light-blue and dark-green stimuli. The chromatic perception disorder is correlated with the severity of PD. It can be concluded from our data that the dysfunction of colour perception is related to the pathophysiology of PD.