To compare the intraocular pressure effect and safety of latanoprost 0.005% given every evening versus PTFC given twice daily.

Inclusion Criteria:

• adults with primary open-angle or pigment dispersion glaucoma, or ocular hypertension
• untreated intraocular pressure should be between 24-36 mm Hg inclusive
• visual acuity should be 5/50 or better in both eyes

Exclusion Criteria:

• presence of exfoliation syndrome or exfoliation glaucoma
• contraindications to study medications
• any anticipated change in systemic hypotensive therapy