All patients were at least 18 years old, with unilateral or bilateral open-angle glaucoma (defined as IOP > 21 mmHg, mean of three consecutive measurements, at any time during the day, at the moment of glaucoma diagnosis) or ocular hypertension (IOP> 25 mmHg, mean of three consecutive measurements, at anytime during the day, at the moment of diagnosis). Glaucoma was defined as a reproducible glaucomatous visual field defect based on GHT outside normal limits and/or PSD lower than 0,5% or glaucomatous changes of the optic disc associated to elevated IOP. A visual acuity (ETDRS) of 20/80 or better was required for randomization.