Eye Health Center

What is glaucoma?

Glaucoma is the name for a group of eye diseases that damage the optic nerve . The optic nerve, which carries information from the eye to the brain, is in the back of the eye. When the nerve is damaged, you can lose your vision.

At first, people with glaucoma lose side (peripheral) vision. But if the disease is not treated, vision loss may get worse. This can lead to total blindness over time.

There are three types of glaucoma.

• Open-angle glaucoma is the most common form in the United States. In this type of glaucoma, the optic nerve is damaged bit by bit. This slowly leads to loss of eyesight. One eye may be affected more than the other. Sometimes much of your eyesight may be lost before you notice it.
• Closed-angle glaucoma is less common. About 10% of all glaucoma cases in the United States are closed-angle. In this type of glaucoma, the colored part of the eye (iris) and the lens block movement of fluid between the chambers of your eye. This causes pressure to build up and the iris to press on the drainage system of the eye. (See a picture of the iris and lens .) A related type is sudden (acute) closed-angle glaucoma. It is often an emergency. If you get this acute form, you will need medical care right away to prevent permanent damage to your eye.
• Congenital glaucoma is a rare form of glaucoma that some infants have at birth. Some children and young adults can also get a type of the disease.

Finding and treating glaucoma early is important to prevent blindness. If you are at high risk for the disease, be sure to get checked by an eye specialist (ophthalmologist) even if you have no symptoms.

Your risk for glaucoma rises after age 40. Race is also a factor. Blacks are more likely than whites to get the disease. You are also at risk if you have diabetes or if a close family member has had glaucoma.

What causes glaucoma?

Damage to the optic nerve is often caused by increased pressure in the eye (intraocular pressure). This can happen when extra fluid builds up in the eye, such as when the eye makes too much fluid or does not drain well. But some cases of glaucoma aren't caused by increased pressure. In these cases, the cause may not be found.

You can get glaucoma after an eye injury, after eye surgery, or because of an eye tumor. Some medicines (corticosteroids) that are used to treat other diseases may cause glaucoma.

What are the symptoms?

If you have open-angle glaucoma, the only symptom you are likely to notice is loss of vision. You may not notice this until it is serious. That?s because, at first, the eye that is not affected makes up for the loss. Side vision is often lost before central vision.