6.18:
Glaucoma: Overview
Glaucoma is characterized by retina and optic nerve damage due to increased intraocular pressure, resulting in irreversible blindness.
Anatomically, the human eye consists of an anterior and a posterior chamber, trabecular meshwork, a cornea, an iris and ciliary body.
The ciliary body epithelium secretes aqueous humor that flows through the trabecular meshwork and drains via the Schlemm's canal, located at the iridocorneal angle.
In a healthy eye, the aqueous humor's secretion rate is balanced by the drainage rate, maintaining normal intraocular pressure.
However, in pathological conditions, the drainage pathway is blocked.
For example, when the trabecular meshwork stiffens, the drainage is slow. So, the fluid accumulates, increasing the intraocular pressure progressively.
Because the iridocorneal angle is open, this case is termed open-angle glaucoma.
Alternatively, when the iris bulges out, it blocks the iridocorneal angle and, thereby, impeding the outflow.
In this situation, the intraocular pressure increases rapidly, causing angle-closure glaucoma.
Both types of glaucoma are managed using either drugs or surgery.
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.