A 6 Month Study Comparing Latanoprost With Timolol in Patients With Open Angle Glaucoma or Ocular Hypertension

Inclusion Criteria: * Unilateral or bilateral primary open angle glaucoma, capsular glaucoma, pigmentary glaucoma or ocular hypertension. * Open angle glaucoma appearing more than 6 months after cataract surgery is recognized as primary open angle glaucoma. (individuals requiring treatment bilaterally must fulfill eligibility criteria for both eyes.) * IOP of 22mmHg or higher obtained during the pre-study period. * Patients currently not treated or on single-drug treatment for the elevated IOP are eligible after a medication free period (wash-out) of: 1. 3 weeks for B-adrenergic antagonists 2. 2 weeks for adrenergic agonists 3. 5 days for cholinergics and oral carbonic anhydrase inhibitors. Exclusion Criteria: * History of acute angle closure. * Severe trauma at any time. * Intraocular surgery or argon laser trabeculoplasty within 6 months. * Current use of contact lenses. * History of severe dry eye syndrome. * Ocular inflammation/infection with three months of inclusion. * Any condition preventing reliable applanation tonometry. * Unacceptable finding at pre-study ocular examination as specified in the Case Report Forms. * In Investigator regards monotherapy insufficient with respect to optic nerve head and/or visual field status. * Treatment of elevated IOP with any topical B-adrenergic antagonist regularly for a period longer than 3 months and/or treatment at any time during 6 months prior to study start. * Cardiac failure, sinus bradycardia, second and third degree of atrio-ventricular block. * Bronchial asthma, history of bronchial asthma or chronic obstructive pulmonary disease. * Having participated in any other clinical study within the last month.