Seniors and Glaucoma
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.
Causes and Risk Factors
Glaucoma is a leading cause of blindness. 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
Symptoms and Diagnosis
- 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
Glaucoma can develop in one or both eyes. The most common type of glaucoma, open-angle glaucoma, has no symptoms at first. It causes no pain, and vision seems normal.
Without treatment, people with glaucoma will slowly lose their peripheral, or side vision. They seem to be looking through a tunnel. Over time, straight-ahead vision may decrease until no vision remains.
Glaucoma is detected through a comprehensive eye exam that includes a visual acuity test, visual field test, dilated eye exam, tonometry, and pachymetry.
A visual acuity test uses an eye chart test to measure how well you see at various distances.
A visual field test measures your side or peripheral vision. It helps your eye care professional tell if you have lost side vision, a sign of glaucoma.
In a dilated eye exam, drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
In tonometry, an instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
With pachymetry, a numbing drop is applied to your eye. Your eye care professional uses an ultrasonic wave instrument to measure the thickness of your cornea.
Although open-angle glaucoma cannot be cured, it can usually be controlled. While treatments may save remaining vision, they do not improve sight already lost from glaucoma.
The most common treatments for glaucoma are medication and surgery.
Medications for glaucoma may be either in the form of eye drops or pills. Some drugs reduce pressure by slowing the flow of fluid into the eye. Others help to improve fluid drainage.
For most people with glaucoma, regular use of medications will control the increased fluid pressure. But, these drugs may stop working over time. Or, they may cause side effects. If a problem occurs, the eye care professional may select other drugs, change the dose, or suggest other ways to deal with the problem.
Laser surgery is another treatment for glaucoma. During laser surgery, a strong beam of light is focused on the part of the anterior chamber where the fluid leaves the eye. This results in a series of small changes that makes it easier for fluid to exit the eye. Over time, the effect of laser surgery may wear off. Patients who have this form of surgery may need to keep taking glaucoma drugs.
Researchers are studying the causes of glaucoma and are looking for ways to improve its diagnosis and treatment. Studies have shown that the early detection and treatment of glaucoma, before it causes major vision loss, is the best way to control the disease. So, if you fall into one of the high-risk groups for the disease, make sure to have your eyes examined through dilated pupils at least every two years by an eye care professional.