Spatial Color Contrast Sensitivity Of Patients Suffering From Chronic Open Angle Glaucoma

Abstract

Purpose: : To investigate the visual losses of patients suffering from chronic open angle glaucoma by using psychophysical measurements of spatial color contrast sensitivity.

Methods: : Twelve glaucoma patients were studied (54.3±10.1 years old). Spatial color contrast sensitivity was evaluated by using stationary chromatic sine wave gratings, 13°x10º of visual field, mean luminance of 15 cd/m² in blue-green, blue-red, and green-red axes (CIE1931: blue=0.141,0.067; green=0.243,0.626; red=0.576,0.382) in four spatial frequencies (0.1, 0.2, 0.5, and 1 cpd), nine different chromatic proportions and one luminance condition (Mullen, 1985). Statistical analysis was two-way ANOVA-Bonferroni’s post-hoc (p<0.05). All patients were examined by an ophthalmologist, tested for C-quant, anomaloscopy, and B-W 30-2 visual perimetry.

Results: : C-quant: Glaucoma patients had mean values expected for the age group. Although three patients had Esd higher than the norms; four patients had Q lower than the norms; three patients were outside the norms for their age group. Rayleigh anomaloscopy: Only 2 glaucoma patients had Color Mix above normative data, and all patients had normal AQ. Moreland anomaloscopy: Eight glaucoma patients had abnormal AQ and Color Mix in comparison with normative data. Visual perimetry: Threshold detection mean for points in the 10-30^o rings was lower in glaucoma patients in comparison with controls (p<0.01). No abnormality for mean deviation and pattern standard deviation values. Spatial color contrast sensitivity: Glaucoma patients had statistically significant lower contrast sensitivity in all chromatic axes and in all spatial frequencies in comparison with controls (p<0.05). There were no preferential axes for the color vision loss. .

Conclusions: : Patients suffering from chronic open angle glaucoma had an impairment of spatial color contrast sensitivity in different chromatic axes. Spatial color contrast sensitivity can be used together with blue-yellow Moreland anomaloscopy as a tool to evaluate visual performance in the early phases of the disease.

Keywords: electrophysiology: clinical • color vision • clinical laboratory testing