Glaucoma

Glaucoma is an eye disease that is caused by an increase in intraocular pressure (IOP) -- this pressure gives the eyeball its round shape. The increase in IOP results from a change in the eye's ability to drain aqueous humor, the fluid circulating inside the eye.

There are two general types of glaucoma: -open-angle and closed-angle (the angle refers to the point where the muscles that keep open the pores that drain the fluid meet.)

The most common type is open-angle glaucoma (accounts for 90% of glaucoma cases); it is the leading cause of blindness in people of African American descent. Normally, open-angle glaucoma is a slowly progressive (or chronic) disease that produces no obvious symptoms until its late stages and occurs in both eyes, although one eye may have a faster progression of the disease than the other. A smaller percentage of people develop closed-angle glaucoma, which is typically acute (occurs more suddenly) and associated with a red, swollen, and painful eye. It is usually the result of a blockage of the pores that drain eye fluid and should be treated urgently to remove the blockage to help avoid permanent vision loss.