A clinical trial of timolol and epinephrine in the treatment of primary open-angle glaucoma.
Forty-seven patients with chronic open-angle glaucoma who required therapy but who had never been treated previously were enrolled in a prospective randomized, long-term clinical trial comparing the effectiveness of 0.5% timolol maleate and 1% epinephrine. Patients were followed for an average of 33 months. There were 20 failures, 18 of which were because of inadequate intraocular pressure (IOP) control (required 20% reduction in outflow pressure). Twelve failures were in the epinephrine group and eight were in the timolol group. During the first year of therapy, 35% compared with 0% of patients failed in the epinephrine and timolol groups, respectively (P less than 0.01). During the later years of the study, the failure rates in the two groups were similar. The results suggest that timolol is superior to epinephrine during the first year of therapy, and likely as effective as epinephrine in the long-term treatment of glaucoma.