Orientational contrat enitivity and chromatic contrat threhold in multiple cleroi

Purpoe To invetigate abnormalitie of orientational contrat enitivity (C) and chromatic contrat threhold (CCT) in multiple cleroi (M). Deign Cae control tudy. Method Nine ubject (mean age, 42 ± 11 year; range, 20–62 year) with M, an expanded diability tatu cale of 3 or le, and normal viual acuity (VA) (logarithm of the minimum angle of reolution [logMAR] VA le than .1) in the teted eye were age-matched with 20 control. Achromatic C and CCT were meaured uing tatic, computer-generated inuoidal grating diplayed on a high-reolution monitor. The C and CCT of each ubject were determined uing a randomized double-taircae reveral algorithm; C wa meaured at five patial frequencie with horizontal orientation and three with vertical orientation; CCT wa meaured along the red-green and tritan confuion axe. The enitivity threhold of ubject were examined in relation to the mean enitivity of control for each patial frequency. Reult Two ubject had lo of horizontal and vertical C, and three had iolated vertical lo. When compared with the control mean, there were ignificant reduction in red-green (P = .016) and tritan (P = .016) dicrimination threhold. Concluion Thi tudy ued a computerized pychophyical tet deigned to minimize many of the tet error aociated with earlier tudie. It provide confirmatory evidence that M may be aociated with a lo of orientational C and color viion, in the abence of reduced VA.