Understanding Glaucoma

by National Institute on Aging

Glaucoma is a group of diseases that can damage the eye's optic nerve and result in vision loss and blindness. While glaucoma can strike anyone, the risk is much greater for people over 60.

There are several different types of glaucoma. Most of these involve the drainage system within the eye. At the front of the eye there is a small space called the anterior chamber. A clear fluid flows through this chamber and bathes and nourishes the nearby tissues.

In glaucoma, for still unknown reasons, the fluid drains too slowly out of the eye. As the fluid builds up, the pressure inside the eye rises. Unless this pressure is controlled, it may cause damage to the optic nerve and other parts of the eye and result in loss of vision.

The most common type of glaucoma is called open-angle glaucoma. In the normal eye, the clear fluid leaves the anterior chamber at the open angle where the cornea and iris meet. When fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.

Sometimes, when the fluid reaches the angle, it passes too slowly through the meshwork drain, causing the pressure inside the eye to build. If the pressure damages the optic nerve, open-angle glaucoma - and vision loss - may result.

There is no cure for glaucoma. Vision lost from the disease cannot be restored. However, there are treatments that may save remaining vision. That is why early diagnosis is important.

Quiz

1. Open-angle glaucoma is caused by an increased pressure in the eye.

TRUE is the correct answer. At the front of the eye, there is a small space called the anterior chamber. Clear fluid flows in and out of the chamber to bathe and nourish nearby tissues. In glaucoma, for still unknown reasons, the fluid drains too slowly out of the eye. As the fluid builds up, the pressure inside the eye rises. Unless this pressure is controlled, it may cause damage to the optic nerve and other parts of the eye and loss of vision.

2. Glaucoma is most common among younger people.

FALSE is the correct answer. While glaucoma can strike anyone, the risk is much greater for people over 60.

3. Glaucoma can be cured.

FALSE is the correct answer. There is no cure for glaucoma. Vision lost from the disease cannot be restored. However, there are treatments that may save remaining vision. That is why early diagnosis is important.

Causes and Risk Factors

Nearly 3 million people have glaucoma, a leading cause of blindness in the United States. Although anyone can get glaucoma, some people are at higher risk. They include

• African-Americans over age 40
• everyone over age 60, especially Mexican-Americans
• people with a family history of glaucoma.

Studies show that glaucoma is

• five times more likely to occur in African-Americans than in whites
• about four times more likely to cause blindness in African-Americans than in whites
• fifteen times more likely to cause blindness in African Americans between the ages of 45-64 than in whites of the same age group.

Quiz

1. Glaucoma rarely leads to blindness.

FALSE is the correct answer. Nearly 3 million people have glaucoma, a leading cause of blindness in the United States.

2. Having a family history of glaucoma puts you at higher risk of developing glaucoma.

TRUE is the correct answer. People with a family history of glaucoma are at higher risk for developing the disease.

3. Whites over the age of 60 are at higher risk for developing glaucoma.

TRUE is the correct answer. Everyone over age 60 is at higher risk for developing glaucoma.

4. African-Americans are more likely to get glaucoma than whites.

TRUE is the correct answer. Glaucoma is five times more likely to occur in African-Americans than whites, about four times more likely to cause blindness in African-Americans than in whites, and fifteen times more likely to cause blindness in African-Americans between the ages of 45-64 than in whites of the same age group.

About the Author

www.nia.nih.gov
NIA, one of the 27 Institutes and Centers of NIH, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. In 1974, Congress granted authority to form NIA to provide leadership in aging research, training, health information dissemination, and other programs relevant to aging and older people.