Glaucoma - Description

Over two million people in the United States have glaucoma. About eighty thousand of these individuals are legally blind because of the disorder. Glaucoma is the leading cause of preventable blindness in the United States. The condition is about three times as common among African Americans as among whites. The risk for glaucoma increases rapidly with age, but the condition can affect any age group, including newborn infants and fetuses.

Glaucoma is actually a class of disorders. More than twenty different forms of the condition have been identified. They all develop in a similar way, however. The amount of aqueous (pronounced a-kwee-us) humor, a watery fluid that fills the inside of the eyeball, begins to build up. As more of this fluid collects, it places greater pressure on all parts of the eye, including the optic nerve. Eventually the excess pressure destroys the nerve.

The many forms of glaucoma are grouped into two large categories: open-angle glaucoma and closed-angle glaucoma. Open-angle glaucoma is a progressive disease. That is, it gets worse over time if not treated. At first, only a few nerve cells in the optic nerve are destroyed. Blind spots develop in areas where those nerve cells are located. Over time, more and more nerve cells are destroyed. A larger and larger area of vision is lost. Eventually, a person may lose his or her sight completely.

Closed-angle glaucoma happens very quickly. Some type of accident or change in the eye causes aqueous humor to build up very suddenly. The effects of glaucoma appear in a very short time.