The Diurnal and Nocturnal Effect of Simbrinza and Timolol on Intraocular Pressure and Ocular Perfusion Pressure

Inclusion Criteria: * Diagnosis of open angle glaucoma or ocular hypertension including pigment dispersion glaucoma and pseudoexfoliation glaucoma. * Age ≥ 18 years, of either gender, or any race/ethnicity Exclusion Criteria: * Females who are currently pregnant or planning to become pregnant during the study period * Contraindications to beta blockers (see below) * Patients currently taking oral beta blocker therapy * Diagnosis of any other form of glaucoma other than open-angle * Schaffer angle grade \< 2 in either eye by gonioscopy * Intraocular surgery within 6 months or laser within 3 months * Inability to safely discontinue all ocular medications for 6 weeks * Patients who smoke or have irregular daily sleep patterns * History of allergy or intolerance to topical carbonic anhydrase inhibitors, or alpha-agonists * Patients who have started or changed glucocorticoids therapy in the last 3 months * Patients who are currently using medical or recreational marijuana * Any use of a non-FDA approved medication for glaucoma in the last 3 months