Glaucoma Biomarkers

Inclusion Criteria: * Either gender. * Any self-declared ethnoracial category. * Greater than or equal to 40 years. * Healthy eyes with the crystalline lens, without glaucoma (cup:disc ratio \< 0.8 both eyes; asymmetry of cup:disc ratio between eyes \< 0.2). * Open angles. * Ability to cooperate for aqueous humor dynamic studies. * Nonprescription and prescription topical ophthalmic products and systemic medications other than those mentioned in the exclusion criteria will be allowed during the study. * Contact lenses removed prior to topical fluorescein instillation, and not used until the end of each fluorophotometry session. * Able to participate on site over the multi-visit study period. Exclusion Criteria: * Women who are pregnant due to IOP changes. * Any form of glaucoma, including extremely narrow angle with complete or partial closure. * Current use of any glaucoma medication, either topically or orally. * Chronic or recurrent inflammatory eye disease. * Ocular trauma within the past 6 months. * Ocular infection or ocular inflammation in the past 3 months. * Clinically significant retinal disease. * Any abnormality preventing reliable fluorophotometry of either eye, such as corneal scarring or severe dry eye that results in punctate fluorescein staining of the cornea. * Intraocular surgery within 6 months. * Serious hypersensitivity to any components of the study medications or risk from treatment with glaucoma medications, such as severe asthma or emphysema. * Subjects must be on a stable regimen for at least 30 days prior to the Visit 1 regarding a chronic systemic medication that may affect IOP (i.e., sympathomimetic agents, beta-blockers, alpha-adrenergic agonists, alpha-adrenergic blockers, calcium channel blockers, angiotensin converting enzyme inhibitors, etc.). Any change of such medication during the study period will result in exclusion. * Use of any glucocorticoid by any route. Subject must be washed out of the glucocorticoid for at least 2 weeks before study entry.