Glaucoma is a disease that damages the eye’s optic nerve. The optic nerve is connected to the retina – a layer of light-sensitive tissue lining the back of the eye -and is made up of many nerve fibers, like an electric cable is made up of many wires. It is the optic nerve that sends signals from your retina to the brain, where these signals are interpreted as the images you see.
In a healthy eye, fluid is produced and flows out of the eye at a rate that maintains a healthy pressure in the eye. There are a number of things that can interfere with this balance. High pressure may cause damage to the delicate nerve fibers over time. Although there may be other causes of glaucoma, most cases are related to pressure.
A few glaucoma patients have pain, redness and halos. However, a person generally has no way of knowing that they are gradually losing vision until sight loss is very advanced. As a result, only about half of the 3 million Americans who have glaucoma are actually aware of it. Fortunately treatment of glaucoma is usually successful in preserving sight when started in time.
People with certain characteristics are more likely to have glaucoma and should be have frequent glaucoma checks:
- Age – From the 40’s on risk increases every year.
- Family history – if someone in your immediate family has glaucoma
- Race – African-Americans and Hispanics have a higher risk of glaucoma
- Nearsighted or farsighted – if glasses are +4 and up or -4 and higher
- High pressure in the eye – may take time before damage occurs
- Injury to the eye
- Thin cornea – the clear windshield of the eye
- Low blood pressure
- Diabetes, migraines or other things that affect blood flow.
Glaucoma is generally diagnosed by checking the pressure of the eye, looking at the optic nerve and testing side vision. Fortunately, these tests are generally part of a routine eye exam. If there is a suspicion of glaucoma then additional tests may help confirm the glaucoma and help in evaluating the proper treatment.
The goal of treatment is to maintain sight. This is generally achieved by lowering the eye pressure. Although diet and healthy life style probably help, there is no conclusive evidence of their success. There are several proven methods of treatment:
- Eye Drops – While these are generally somewhat effective in lowering pressure, all drops have side effects, are impossible to take as directed and are very expensive. Poor use of eye drops is a major cause of vision loss in glaucoma patients. Large national studies have shown that other methods often give better results.
- Laser – Lasers are as effective as eye drops in lowering pressure and studies have shown patients do better over a period of time. It has been used longer than most of the eye drops and has no reported side effects. It takes about 10 minutes to perform and is good for years. Laser works best if done before drops are started.
- Surgery – Because drops have such a poor record of success, Europeans perform surgery prior to using drops and have noteably increased pressure control rates. Surgery has significant side effects so in this country surgery is reserved for only severe cases that cannot be successfully treated by other means.
In summary, glaucoma is a serious condition that blinds many people but in most cases can be controlled with proper treatment. Regular check-ups will do much to prevent vision loss from glaucoma.