The purpose of this study is to compare the fixed combination (BID) [Brinzolamide 10 mg/mL / Brimonidine 2 mg/mL eyes drops, suspension] to the unfixed combination (BID) [Brinzolamide 10 mg/mL eye drops, suspension plus Brimonidine 2 mg/mL eyes drops, solution] with respect to intraocular pressure (IOP)-lowering efficacy.

This study is divided into 2 phases conducted in sequence for a total of 6 visits: Phase I (Screening/Eligibility) which includes a Screening Visit, followed by 2 Eligibility Visits (E1 and E2) and Phase II (Treatment/Follow-up) which includes 3 visits at Week 2, Week 6, and Month 3. Following washout of any IOP-lowering medication, subjects who meet all inclusion/exclusion criteria at both Eligibility visits and had IOP measurements within the specified range during this period will be randomized to Phase II.

Inclusion Criteria:

• Diagnosis of open-angle glaucoma or ocular hypertension insufficiently controlled on monotherapy or currently on multiple IOP-lowering medications;
• Mean IOP measurements within guidelines specified in the protocol. Must not be > 36 mmHg at any time point;
• Able to understand and sign an informed consent form;
• Other protocol-specified inclusion criteria may apply.

Exclusion Criteria:

• Women of childbearing potential who are pregnant, test positive for pregnancy, intend to become pregnant during the study period, breast-feeding, or not in agreement to use adequate birth control methods throughout the study;
• Severe central visual field loss in either eye;
• Unable to safely discontinue all IOP-lowering ocular medication(s) for a minimum of 5 (± 1) to 28 (± 1) days prior to E1 Visit;
• Chronic, recurrent or severe inflammatory eye disease;
• Ocular trauma within the past 6 months;
• Ocular infection or ocular inflammation within the past 3 months;
• Clinically significant or progressive retinal disease such as retinal degeneration, diabetic retinopathy, or retinal detachment;
• Best-corrected visual acuity (BCVA) score worse than 55 ETDRS letters (equivalent to approximately 0.60 logMAR, 20/80 Snellen, or 0.25 decimal);
• Other ocular pathology (including severe dry eye) that may preclude the administration of α-adrenergic agonist and/or topical carbonic anhydrase inhibitor (CAI);
• Intraocular surgery within the past 6 months;
• Ocular laser surgery within the past 3 months;
• Any abnormality preventing reliable applanation tonometry;
• Any conditions including severe illness which would make the Subject, in the opinion of the Investigator, unsuitable for the study;
• History of active, severe, unstable or uncontrolled cardiovascular, cerebrovascular, hepatic, or renal disease that would preclude safe administration of a topical α-adrenergic agonist or CAI;
• Recent (within 4 weeks of the E1 Visit) use of high-dose (> 1 g daily) salicylate therapy;
• Current or anticipated treatment with any psychotropic drugs that augment adrenergic response (eg, desipramine, amitriptyline);
• Concurrent use of monoamine oxidase inhibitors (MAOI);
• Concurrent use of glucocorticoids administered by any route;
• Therapy with another investigational agent within 30 days prior to the Screening Visit;
• Hypersensitivity to α-adrenergic agonist drugs, topical or oral CAIs, sulfonamide derivatives, or to any component of the study medications;
• Less than 30 days stable dosing regimen before the Screening Visit of any medications (excluding IOP-lowering treatments) or substances administered by any route and used on a chronic basis that may affect IOP, including but not limited to β-adrenergic blocking agents;
• Use of any additional topical or systemic ocular hypotensive medication during the study;
• Other protocol-specified exclusion criteria may apply.