Included woman of childbearing potential, pregnancy, systemic contra-indication to beta-blocker therapy, argon laser trabeculoplasty three months before screening visit, any history of filtering surgery, ocular surgery or uveitis three months before screening visit, hypersensitivity to any compound of the study drugs, concomitant use of any experimental drug, any condition in which treatment with beta-blocker is contraindicated or any other abnormal and/or ocular condition or symptom that would prevent study participation, according to the judgment of the investigator. The use of systemic beta-blocker, if needed, was allowed and not considered an exclusion criterion. Latanoprost non-responders defined as lower than 15% IOP reduction after run-in period with latanoprost monotherapy were excluded from the study.