Overview

Second leading cause of blindness in adults in the US following age-related macular degeneration (AMD)

∼ 2.3 million cases of glaucoma in the US

• Vision impairment in ∼ 10% of patients

• Blindness in ∼ 5% of patients

• Open-angle glaucoma is more common than angle-closure glaucoma

Aqueous humor is produced by the ciliary body on the iris, flows from the posterior chamber through the pupil into the anterior chamber, and then drains back into the venous system via the trabecular meshwork in the angle of the anterior chamber.

Physiologically, the flow of aqueous humor against resistance generates an average intraocular pressure (IOP) between 10–21 mm Hg.

Any process that disrupts the flow of aqueous humor (e.g., adhesion of the iris to the lens) may raise intraocular pressure and lead to optic nerve damage and visual impairment (e.g., glaucomatous optic neuropathy). (See the pathophysiology of “Open-angle glaucoma” and “Angle-closure glaucoma” below.)