The purpose of this study is to demonstrate that fixed combination of latanoprost and timolol (PhXA41) has better IOP lowering effect than the individual monotherapies.

Inclusion Criteria:

• Unilateral or bilateral primary open angle glaucoma, capsular glaucoma, pigmentary glaucoma or ocular hypertension.
• Patients currently on IOP reducing therapy: IOP greater than or equal to 25mmHg (two IOP determinations at pre-study separated by at least one hour) OR Patients without IOP reducing therapy: IOP greater than or equal to 30mmHg (two IOP determinations at pre-study separated by at least one hour).

Exclusion Criteria:

• History of acute angle closure or closed/barely open anterior chamber angle.
• Current use of contact lenses.
• Ocular surgery or argon laser trabeculoplasty (ALT) within three months prior to pre-study visit.
• Ocular inflammation/infection occurring within three months prior to pre-study visit.
• Hypersensitivity to benzalkonium chloride or to any other component of the study drug solutions.
• Other abnormal ocular condition or symptom preventing the patient from entering the study, according to the investigator's judgement.
• Cardiac failure, sinus bradycardia, second and third degree of atrioventricular block. (The routines for prescribing topical B-blocking agents will be followed.
• Bronchial asthma, history of bronchial asthma or chronic obstructive pulmonary disease. (The routines for prescribing topical B-blocking agents will be followed).
• Pregnancy
• Women of childbearing potential who has not used adequate contraceptive methods during the last three months.
• Inability to adhere to treatment/visit plan.
• Have participated in any other clinical study within one month prior to pre-study visit.