Glaucoma
Glaucoma is a group of diseases that can lead to damage to the eye's optic nerve and result in blindness.
Open-angle glaucoma, the most common form of glaucoma, affects about 3 million Americans--half of whom don't know they have it. It has no symptoms at first. But over the years it can steal your sight. With early treatment, you can often protect your eyes against serious vision loss.
What is the optic nerve?
The optic nerve is a bundle of more than 1 million nerve fibers. It connects the retina, the light-sensitive layer of tissue at the back of the eye, with the brain. A healthy optic nerve is necessary for good vision.
How does glaucoma damage the optic nerve?
In many people, increased pressure inside the eye causes glaucoma. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of this space and nourishes nearby tissues.
The fluid leaves the anterior chamber at the angle where the cornea and iris meet. When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.
Open-angle glaucoma gets its name because the angle that allows fluid to drain out of the anterior chamber is open. However, for unknown reasons, the fluid passes too slowly through the meshwork drain. As the fluid builds up, the pressure inside the eye rises. Unless the pressure at the front of the eye is controlled, it can damage the optic nerve and cause vision loss.
There are many other types of glaucoma. Your doctor will explain to you what type of glaucoma you have.
Who is at risk?
Although anyone can get glaucoma, some people are at higher risk than others. They include:
- fro-Americans over age 40
- Everyone over age 60
- People with a family history of glaucoma.
What are the symptoms of glaucoma?
At first open-angle glaucoma has no symptoms. Your vision stays normal and there is no pain. As glaucoma remains untreated, people may notice that although they see things clearly in front of them, they miss objects to the side and out of the corner of their eye.
Without treatment, people with glaucoma may find that they suddenly have no side vision. It may seem as though they are looking through a tunnel. Over time, the remaining forward vision may decrease until there is no vision left.
How is glaucoma detected?
Most people think that they have glaucoma if the pressure in their eye is increased. This is not always true. High pressure puts you at risk for glaucoma. It may not mean that you have the disease.
Whether or not you get glaucoma depends on the level of pressure that your optic nerve can tolerate without being damaged. This level is different for each person. Although normal pressure is usually between 12-21 mm Hg, a person may have glaucoma even if the pressure is in this range. That is why an eye examination is very important.
To detect glaucoma, the following tests should be performed: visual acuity, visual field, pupil dilation, and tonometry.
Can glaucoma be treated?
Yes. Although you will never be cured of glaucoma, treatment often can control it. This makes early diagnosis and treatment important to protect your sight.
Glaucoma treatments include:
- Medicine: It is in the form of eye drops and pills. Some cause the eye to make less fluid. Others lower pressure by helping fluid drain from the eye.
- Laser surgery: Laser surgery helps fluid drain out of the eye. It is often done after trying medication.
In many cases, you will need to keep taking glaucoma drugs even after laser surgery.
What can you do to protect your vision?
If you are being treated for glaucoma, be sure to take your glaucoma medicine every day and see your eye care professional regularly.
You can also help protect the vision of family members and friends who may be at high risk for glaucoma - Afro-Americans over age 40 and everyone over age 60. Encourage them to have a dilated examination every two years.
For more information about glaucoma you may wish to view the following websites:
