Glaucoma

Glaucoma

Glaucoma is a group of eye disorders that cause blindness by hurting the optic nerve, which is the large nerve that is responsible for vision. In glaucoma, the optic nerve damage is related to a change in the fluid pressure that circulates around the eyeball. In many cases, Glaucoma occurs when the eye's fluid pressure is high, but it can also occur when the pressure is measured as normal.

Fluid circulating inside the front portion of the eye is produced by a structure called the ciliary body, which is located behind the iris. This fluid moves through the opening of the pupil, passes into the space between the iris and the cornea, and drains out of the eye through a tissue called the angle. With glaucoma, the passing of fluid through the angle is either reduced or suddenly stops, and amounts of fluid inside the eye increase. This high fluid pressure hurts the nerve fibers and the eye's optic nerve and causes blind spots. It may lead to blindness in some cases.

Glaucoma is a leading cause of blindness in the United States. It tends to run in families and currently affects about 3 million Americans. Although the illness is five times more common in African-Americans than in Caucasians after age 40, the risk of glaucoma goes up with age for people of ethnic backgrounds. Chronic glaucoma, which affects 1 percent to 2 percent of Americans older than 40, is much more common than acute glaucoma.

In checking for glaucoma, your doctor will want to know if any members of your family have had the illness. Then they will also ask whether you have noticed any recent changes in your peripheral vision. After asking about your family health history, your doctor will look for the symptoms of acute glaucoma.

Symptoms

Although open-angle glaucoma and acute glaucoma both cause blindness, their symptoms are very different.

Open-angle glaucoma - With this form of glaucoma, the loss of vision occurs so gradually it is rarely noticed. However, as eye damage increases, you will eventually find that you have lost a lot of areas of your peripheral vision, especially the field of vision near your nose. As larger areas of your peripheral vision fade, you may develop tunnel vision -- vision that has narrowed so you see only what is directly in front of you. If glaucoma is not treated, even this narrowed vision disappears into blindness. Once gone, areas of lost vision cannot be restored.

Acute glaucoma (closed-angle glaucoma) - Symptoms of acute glaucoma occur suddenly and may include blurred vision, halos around lights at night, a haziness in the cornea, pain and redness in the eye, headache, nausea and vomiting, and extreme weakness.

Prevention

Right now, although there is no way to prevent glaucoma, there are many successful treatments available to prevent the blindness caused by glaucoma. Because the gradual vision loss of chronic glaucoma may not be noticed until it is too late, regular eye examinations, dilated exams of the optic nerve, and screening tests of the visual field are essential for all persons aged 40 and older, especially is your family has a history of glaucoma.

Treatment

Treatment of open-angle glaucoma usually begins with prescription eyedrops. These eyedrops lower pressure inside the eyeball, either by causing the eye to produce less fluid or by helping fluid to drain more. As an alternative to medication or when medication does not control glaucoma, laser surgery can be done. This surgery, also called laser trabeculoplasty, uses a laser to make the openings in the eye's drainage network larger. If medication and laser surgery are unsuccessful, conventional eye surgery may be necessary to make a new opening for fluid