A comparison of the effects of betaxolol, timolol, and pilocarpine on visual function in patients with open-angle glaucoma.

Abstract

The author compares the effect of betaxolol, timolol, and pilocarpine on visual functions in patients with glaucoma. Sixty-eight patients with early glaucoma were randomly allocated to betaxolol, timolol, or pilocarpine treatment and their visual fields, motion detection, and contrast sensitivity were studied over a 24-month period. A subset of the betaxolol and timolol group were also followed with short-wave automated perimetry. One eye of each patient was used in the analysis. All three drugs reduced pressure effectively. Pilocarpine and timolol were not significantly different from each other and both produced a more marked pressure reduction than betaxolol. There were no significant differences between the drugs on the visual fields, contrast sensitivity, or motion detection. Betaxolol appeared to have a better impact on the blue-yellow sensitivity of the upper nasal and upper temporal visual field quadrants than timolol. In spite of a greater pressure reduction, timolol did not have a more favorable effect on visual function. In the short-wave automated perimetry, the betaxolol did marginally better than timolol. The apparent dissociation between pressure reduction and protection of visual function deserves further study.