CHROMATIC AND LUMINANCE SYSTEMS DEFICITS IN GLAUCOMA

The purpose of this study was to compare the effects of glaucoma, at d ifferent stages of the disease process, on the two color-opponent syst ems and on the luminance system, Discrimination thresholds were measur ed along the two equiluminant cardinal color axes (RG and YV) and alon g an achromatic luminance axis (LD) in 27 patients with open-angle gla ucoma (GAG) and in 13 glaucoma suspects, Patients with OAG showed incr eased thresholds along all three axes. The threshold increases correla ted significantly with the level of visual field loss, For glaucoma su spects, thresholds were also increased along all three axes. A subgrou p of patients with GAG, those with pigmentary glaucoma, showed minimal increases in threshold along the RG axis. To further investigate this finding an additional 15 patients, seven with primary OAG and eight w ith pigmentary glaucoma were run in a two-alternative forced-choice ex periment. For patients with pigmentary glaucoma, thresholds were incre ased less along the RG axis, The results of the study for OAG patients and glaucoma suspects are consistent with deficits in the two color-o pponent systems, and in the luminance system.