Illinois Society for the Prevention of Blindness

Glaucoma is a group of eye diseases in which the pressure inside the eye rises above normal. This excessive pressure can destroy both retinal cells and optic nerve fibers and blind the eye.

While glaucoma can occur without warning, the following symptoms are possible.

At its onset, open-angle glaucoma usually has no symptoms.

Glaucoma treatment is aimed at controlling the eye's fluid pressure as a means of slowing disease progression. Such treatment does not cure the disease.

The most reliable way to detect open-angle glaucoma is through a comprehensive eye examination with dilated pupils--which, when indicated, includes a visual field test.

In an eye with open-angle glaucoma, the aqueous humor drains too slowly through the channel system, creating a chronic rise in fluid pressure inside the eye. This elevated pressure may gradually interrupt the metabolic processes of cells in the optic nerve, leading to a progressive destruction of nerve fibers that are essential for vision.

Open-angle glaucoma is the most common form of glaucoma, an eye disease that is a leading cause of blindness in the United States.

There are two major kinds of glaucoma.

While chronic glaucoma cannot be cured, it can be controlled and held in check, chiefly through the use of daily medications that either increase fluid removal from the eye or decrease the amount of fluid produced within the eye.

The loss of sight is gradual. It begins as loss of side vision, then it continues toward the center of vision, until finally all sight is destroyed. Because the visual loss is gradual in the early stages of the disease, few signs of the disorder are recognized.