Glaucoma is a condition that develops when the fluid pressure in the eye is abnormally high. This causes damage to the fibers of the optic nerve, or the nerve of vision. Some glaucoma cases may be associated with normal pressure. This condition usually occurs in older adults.

What is going on in the body?

A clear fluid called aqueous humor is constantly produced within the eye. This liquid is not the same as tears, which appear outside the eye. As new fluid is produced, an equal amount flows out of the eye. The old fluid drains out of the eye through a special filtration area at the root of the iris. The iris is the part of the eye that gives the eye its color. A blockage in the filtration area can cause a fluid imbalance, which makes pressure build up. If this problem is not found for months or years, damage to the optic nerve will occur. The optic nerve is made up of a large number of nerve fibers. The nerve is like an electric cable containing many wires. When glaucoma damage occurs, these fibers are lost, causing blind spots to develop. The blind spots can be seen when a doctor looks into the eye. The blind spots can be plotted on a chart. This test is called a visual field test.

What are the causes and risks of the condition?

The main cause of most glaucoma cases is fluid build up. Some cases, however, are related to injury to the eye, use of corticosteroid medications, or previous eye surgery. The risk of developing glaucoma is higher in:

The acute form of glaucoma is more common in people of Asian descent.