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.