Objective: To compare the effect on intraocular pressure of latanoprost versus timolol plus dorzolamide in open-angle glaucoma.

Methods: Thirty-five patients with open-angle glaucoma were randomized, 18 to latanoprost once daily and 17 to timolol plus dorzolamide twice daily. Intraocular pressure and ocular side effects were recorded at baseline, and after 2 weeks and 3 months of treatment.

Results: Latanoprost reduced the intraocular pressure 1.09 and 1.58 mm Hg more than timolol plus dorzolamide after 2 weeks and 3 months of treatment, respectively. These differences were statistically significant (p<0.05) at the end of the study. After 3 months of treatment, 32.3% of the eyes in the latanoprost group reduced the intraocular pressure in 30% or more with respect to baseline, while 15.6% of the eyes in the timolol plus dorzolamide group achieved this reduction.

Conclusions: Latanoprost administered once daily reduced the intraocular pressure at least as well as timolol plus dorzolamide twice daily in patients with open-angle glaucoma.