The effect of 1.5% timolol maleate on intraocular pressure.

A controlled trial was instituted to compare the effect on intraocular pressure of topical administration of timolol maleate with epinephrine hydrochloride. A bottling error by the manufacturer resulted in the placebo bottles containing 1.5% timolol maleate. This drug given twice a day for two weeks significantly reduced intraocular pressure and produced no side effects.