GLAUCOMA
Glaucoma is the leading cause of blindness in the United States, especially for older people. But the loss of sight from glaucoma is preventable if you get treatment early enough.
Glaucoma is a disease of the optic nerve. The optic nerve carries the images we see to the brain. Many people know that glaucoma has something to do with the pressure inside the eye. The higher the pressure inside the eye, the greater the chance of damage to the optic nerve.
The optic nerve is like an electric cable containing a huge number of wires. Glaucoma can damage nerve fibers, causing blind spots to develop.
Often people don't notice these blind areas until much optic nerve damage has already occurred. If the entire nerve is destroyed, blindness results.
Early detection and treatment by your ophthalmologist are the keys to preventing optic nerve damage and blindness from glaucoma.
What Causes Glaucoma?
Clear liquid, called the aqueous humor, flows in and out of the eye. This liquid is not part of the tears on the outer surface of the eye. You can think of the flow of aqueous fluid as a sink with the faucet turned on all the time.
If the "drainpipe" gets clogged, water collects in the sink and pressure builds up. If the drainage area of the eye - called the drainage angle - is blocked, the fluid pressure within the inner eye may increase, which can damage the optic nerve.
Types of Glaucoma
Chronic open-angle glaucoma: This is the most common glaucoma. It occurs as a result of aging. The "drainpipe," or drainage angle of the eye, becomes less efficient with time, and pressure within the eye gradually increases.
If this increased pressure results in optic nerve damage, it is known as chronic open-angle glaucoma. Over 90% of adult glaucoma patients have this type of glaucoma.
Chronic open-angle glaucoma can damage vision so gradually and painlessly that you are not aware of trouble until the optic nerve is already badly damaged.
Angle-closure glaucoma: Sometimes the drainage angle of the eye may become completely blocked.
It is as though a sheet of paper floating near a drain suddenly drops over the opening and blocks the flow out of the sink. In the eye, the iris may act like the sheet of paper closing off the drainage angle.
When eye pressure builds up rapidly, it is called acute angle-closure glaucoma.
The symptoms include:
- Blurred vision
- Severe eye pain
- Headaches
- Rainbow haloes around lights
- Nausea and vomiting
If you have any of these symptoms, call your ophthalmologist immediately. Unless an ophthalmologist treats acute angle-closure glaucoma quickly, blindness can result.
More gradual and painless closing of the angle is called chronic angle-closure glaucoma. It occurs more frequently in people of African and Asian ancestry.
Detection of Glaucoma
Regular eye examinations by your ophthalmologist are the best way to detect glaucoma. An ophthalmologist is a medical eye doctor. Your ophthalmologist can detect and treat glaucoma.
During a complete and painless examination, your ophthalmologist will:
- Measure your intraocular pressure (tonometry)
- Inspect the drainage angle of your eye (gonioscopy)
- Evaluate any optic nerve damage (ophthalmoscopy)
- Test the visual field of each eye (perimetry)
Some of these tests may not be necessary for every person. You may need to repeat these tests on a regular basis, to determine if glaucoma damage is increasing over time.
Who Is at Risk for Glaucoma?
High pressure alone does not mean that you have glaucoma. Your ophthalmologist puts together many kinds of information to determine your risk for developing the disease.
The most important risk factors include:
- Age
- Near-sightedness
- African ancestry
- A family history of glaucoma
- Past injuries to the eyes
- A history of severe anemia or shock
Your ophthalmologist will weigh all of these factors before deciding whether you need treatment for glaucoma, or whether you should be monitored closely as a glaucoma suspect.
This means your risk of developing glaucoma is higher than normal, and you need to have regular examinations to detect the early signs of damage to the optic nerve.
What Is Your Part In Treatment?
Treatment for glaucoma requires a "team" made up of both you and your doctor. Your ophthalmologist can prescribe treatment for glaucoma, but only you can make sure you take your eye drops or pills.
Never stop taking or change your medications without first consulting your ophthalmologist. Frequent eye examinations and tests are critical to monitor your eyes for any changes. Remember, it is your vision, and you must do your part to maintain it.
Loss of Vision Can Be Prevented
Regular medical eye exams may help prevent unnecessary vision loss.
You Should have an Examination:
Every year:
- if you are age 50 and over
- If a family member has glaucoma
- If you are of African ancestry
- If you have had a serious eye injury in the past
- If you are taking steroid medications