6.18: Glaucoma: Overview
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal of Schlemm are located at the iridocorneal angle, where the iris and cornea meet.
In glaucoma, the iridocorneal angle becomes blocked, causing an imbalance between aqueous humor secretion and drainage. When the trabecular meshwork becomes stiff, the outflow of aqueous humor slows down. Consequently, the aqueous humor gradually accumulates in the anterior chamber, increasing intraocular pressure. This condition is referred to as open-angle glaucoma because the iridocorneal angle remains open. Angle-closure glaucoma occurs when the iris bulges and obstructs the iridocorneal angle, leading to a sudden rise in intraocular pressure. Both types of glaucoma can be managed with medications or surgical interventions.
