
Application of the fixed combination 2% dorzolamide hydrochloride/0.5% timolol maleate ophthalmic solution (Cosopt, Merck, Sharp & Dohme) resulted in a significant decrease in IOP 6 and 8 weeks after the onset of therapy in patients with ocular hypertension or primary open-angle glaucoma whose IOP had not been controlled by 0.5% timolol alone. The daytime and nighttime IOP values also were significantly reduced at the same time points compared with baseline.