Glaucoma - Topic Overview
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
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
- 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
- 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
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.