Evaluation of timolol in chronic open-angle glaucoma. Once a day vs twice a day.

Regimens of once-a-day or twice-a-day 0.25% timolol ophthalmic solution were compared for efficacy and tolerability in a four-week study of 41 patients with chronic open-angle glaucoma and elevated, untreated intraocular pressure. Significant reductions in IOP relative to untreated baseline values were achieved within a range of 18% to 25%. No significant between-group differences were noted, although the twice-a-day group had somewhat lower IOPs at each evaluation point and the once-a-day group had somewhat fewer subjective symptoms of local irritation. A statistically significant decrease from baseline in mean pulse rate was noted in the twice-a-day treatment group after two weeks; no clinically significant or serious adverse reactions occurred in any patient. Both once-daily and twice-daily administrations of 0.25% timolol ophthalmic solution were found to be effective and well tolerated in the population studied.