Glaucoma is a group of eye disorders that lead to progressive damage to the optic nerve. People with glaucoma can lose nerve tissue, resulting in vision loss. The optic nerve is a bundle of about 1 million individual nerve fibers that transmits the visual signals from the eye to the brain. In the most common form of glaucoma, primary open-angle glaucoma, the fluid pressure inside the eye increases. This increase in pressure may cause progressive damage to the optic nerve and loss of nerve fibers. Vision loss may result. Advanced glaucoma may even cause blindness.
Glaucoma is the second-leading cause of blindness in the U.S. It most often occurs in people over age 40,although an infant (congenital) form of glaucoma exists. People with a family history of glaucoma, African Americans over the age of 40 and Hispanics over the age of 60 have an increased risk of developing glaucoma. Other risk factors include thinner corneas, chronic eye inflammation and taking medications that increase the pressure in the eyes.
The most common form of glaucoma, primary open-angle glaucoma, develops slowly and usually without any symptoms. Many people are not aware they have the condition until they have significant vision loss. Initially, glaucoma affects peripheral or side vision, but it can advance to central vision loss. If left untreated, glaucoma can lead to significant vision loss in both eyes, and may even lead to blindness.
A less common type of glaucoma, acute angle-closure glaucoma, usually occurs abruptly due to a rapid increase of pressure in the eye. Its symptoms may include severe eye pain, nausea, redness in the eye, seeing halos or colored rings around lights and blurred vision. This is an emergency condition in which severe vision loss can occur quickly; see your optometrist immediately.
Glaucoma cannot currently be prevented. But if it is diagnosed and treated early, it can usually be controlled. Medication or surgery can slow or prevent further vision loss. However, vision already lost to glaucoma cannot be restored. That is why the American Optometric Association recommends an annual dilated eye examination for people at risk for glaucoma. Depending on your specific condition, your doctor may recommend more frequent examinations.