Inclusion Criteria:

• · Male or female > 18 years of age

  • Diagnosis of open-angle glaucoma or ocular hypertension
  • IOP > 16 mm Hg in each eye at the latanoprost -treated baseline evaluation
  • Presently on latanoprost monotherapy for at least 6 weeks
  • Ability to provide informed consent and likely to complete all study visits

Exclusion Criteria:

• · Known contraindication or allergy to brimonidine or any of its components

  • Subjects must be naive to brimonidine 0.2% or brimonidine Purite 0.15% and dorzolamide 2%
  • Uncontrolled systemic disease
  • Active ocular disease other than glaucoma or ocular hypertension (e.g. uveitis, ocular infections, or severe dry eye). Patients with chronic mild blepharitis, cataract, age-related macular degeneration, or background diabetic retinopathy may be enrolled at the discretion of the investigator.
  • Required use of ocular medications other than the study medications during the study (intermittent use of artificial tear product is allowed).
  • Corneal abnormalities
  • History of intraocular surgery within the last 3 months
  • Female patients of childbearing potential who are pregnant, lactating, planning a pregnancy, or not using a reliable form of birth control
  • Visual field loss, which in the opinion of the investigator, is functionally significant, or evidence of progressive visual field loss within the last year.