24-Hour Intraocular Pressure With Brinzolamide/Timolol Versus Brimonidine/Timolol

Inclusion Criteria: * Patient has open-angle glaucoma and is older than 29 years * Patients should exhibit typical disc, or field changes and an untreated morning IOP greater than 25 mm Hg * Patients are treated for at least 3 months with travoprost and should have demonstrated at least a 20% morning IOP reduction * Patient deemed by PI to require adjunctive therapy to obtain desired target IOP * Patient should exhibit IOP greater than 18 mm Hg on travoprost monotherapy (2 separate IOP readings at 10:00) * Patient has mild to moderate glaucoma (field loss more than 16 dB; cupping 0.8 or less) * Distance best corrected Snellen visual acuity at least 0.1 * No contraindications to travoprost, brimonidine, brinzolamide and β-blockers * No history of lack of response (\<10% morning IOP reduction) to any medication * Patient can understand the instructions and adhere to medications Exclusion Criteria: * Female patient of childbearing potential or lactating mother * History of trauma, inflammation, surgery * History of past use of steroids (within 2 months), severe dry eyes and use of contact lenses * Signs of ocular infection, except blepharitis * Evidence of corneal abnormality that may affect IOP measurements etc * Closed angle * History of non-compliance