Types Of Glaucoma - Glaucoma: Eye Care

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Types of glaucoma

Although 25–30 types of glaucoma exist, the following are among the more common:

Chronic open-angle glaucoma. This is the most common form of the disease, accounting for more than 90% of all cases. It strikes black and Hispanic people far more frequently than whites, is most prevalent in people over 60, and tends to run in families.

The name chronic open-angle glaucoma comes from the fact that the angle through which fluid drains from the anterior chamber of the eye remains open (see Figure 6), yet the aqueous humor drains out too slowly, leading to fluid backup and a gradual but persistent elevation in pressure. Ultimately this damages the optic nerve and causes vision loss if not treated in time and controlled by medication. Because the condition is generally asymptomatic in its early stages, regular eye exams are important, especially for anyone at increased risk.

Acute closed-angle glaucoma. In acute closed-angle glaucoma, the pressure in the eye rises rapidly as the angle between the iris and cornea narrows and the iris suddenly blocks the trabecular meshwork, preventing fluid from flowing out. When this form of the disorder occurs, the eyeball quickly hardens and the pressure causes pain and blurred vision. Also, people often see halos — colored rings around lights.

Low-tension glaucoma. In this less common condition, the optic nerve suffers damage typical of glaucoma, but at normal eye pressures. The diagnosis is often made after there has been some vision damage, but more sensitive diagnostic techniques are making it possible to detect this disease earlier, before damage occurs. After other possible causes of the optic nerve damage and visual loss have been eliminated, lowering the pressure even further with medication, surgery, or both will usually stabilize the condition.

Congenital glaucoma. This is a rare condition present at birth and often inherited. It is attributed to a structural defect in the drainage angle and is frequently found in both eyes.

Secondary glaucoma. Secondary glaucoma may develop as a result of some other eye problem — such as longstanding inflammation, injury, cataract, diabetes, or blood vessel blockage in the eye — or as an effect of some medications (most typically, corticosteroids).

Last updated:	June 19, 2007