Test-retest reliability of the CSV-1000 contrast test and its relationship to glaucoma therapy.

PURPOSE To determine the relationship between changes in contrast sensitivity, if any, after glaucoma therapy and the test-retest reliability of the CSV-1000 contrast sensitivity test. METHODS Patients with primary open angle glaucoma (N = 16) were retrospectively evaluated to determine changes in visual function, as measured by contrast sensitivity, after beta-blocker therapy. A control group (N = 24) of normally sighted patients was tested and retested on contrast sensitivity. For the control group, the coefficients of repeatability (95% confidence interval for test-retest variability [COR]) were calculated for each spatial frequency. The CORs were compared to the changes in vision found after therapy in the patients with glaucoma. RESULTS The group with glaucoma showed a significant improvement (P < .01) in contrast sensitivity at all spatial frequencies. The test-retest variance for normals, as measured by the COR, was smaller than the mean differences in contrast sensitivity before and after therapy at all spatial frequencies, expect 18 cyc/deg. CONCLUSIONS Visual function in patients with glaucoma, as measured by contrast sensitivity, does improve after beta-blocker therapy. Further, the CSV-1000 is a clinically reliable tool for monitoring these changes.