Glaucoma, a disease that damages the eye’s optic nerve, is a leading cause of blindness for people over age 60. Fortunately, blindness from glaucoma can often be prevented with early diagnosis and treatment, says Andrew Spinak, MD of Spinak Medical Eye Center and on staff at Nyack Hospital.
There are a number of treatments available, ranging from prescription eye drops to laser treatment to eye surgery. A recent innovation in glaucoma treatment involves combining cataract surgery with the insertion of tiny tubes to drain fluid in the eye.
Dr. Spinak answers common questions he receives from patients about glaucoma.
Q: What is glaucoma and what causes it?
A: No one knows what causes most glaucoma. The risk of the disease increases with age and generally appears after age 40. It usually happens when the eye makes too much fluid or does not drain fluid as well as it should. This results in fluid building up in the front part of the eye. The extra fluid increases pressure in the eye, which squeezes on the tiny nerve fibers that make up the optic nerve and causes them to die.
Q: Does glaucoma cause symptoms?
A: The most common type of glaucoma, called open-angle glaucoma, is painless and causes no vision change at first. That is why it is so important to go for annual glaucoma screenings. As with many diseases, the earlier glaucoma is diagnosed, the more successful the treatment is likely to be. In more advanced cases of glaucoma, tiny blind spots develop in a person’s vision where bundles of nerves have died. If it is left untreated, glaucoma can lead to blindness.
Q: What does a glaucoma exam consist of?
A: A complete glaucoma screening involves several steps. The ophthalmologist or optometrist will measure your eye pressure, inspect drainage in your eye, examine your optic nerve for damage, take a picture or computer measurement of your optic nerve to see if it has changed over time, and test your vision. You may get an optical coherence tomography (OCT) ultrasound, which shows whether nerves have thinned out or died.
The gold standard for testing for glaucoma is the visual field test. The most common visual field test uses a light spot that is repeatedly presented in different areas of your field of vision. The test shows how your eye nerves are working. If you don’t see light in certain areas, it indicates the nerves in that area have died.
Q: What is the goal of treatment?
A: The goal of treating glaucoma is to manage it and slow it down. Currently, there is no cure. Which treatment a doctor selects depends on how quickly or aggressively the glaucoma is affecting the nerves of the eye. We may use eye drops, laser surgery, traditional eye surgery or a combination. Some patients who are faced with the cost, side effects and inconvenience of a lifetime of eye drops opt for laser surgery. Others choose eye drops because they prefer to avoid any type of eye procedure.
Q: How do eye drops treat glaucoma?
A: Eye drops for glaucoma must be used every day, sometimes several times a day. Some drops reduce the amount of fluid in the eye, while others reduce pressure by promoting fluid drainage. Some eye drops can cause side effects such as dryness, red eyes, and blurred vision.
Q: How does laser treatment help?
A: Laser treatment promotes fluid drainage. It is effective about 70% of the time. In this outpatient procedure, we use a laser to open up the filtering system in the eye to make the drainage work better. This lets the fluid flow out properly and reduces eye pressure. The laser treatment is quick, easy and can be done in the doctor’s office. It generally works for between two and five years and can be repeated up to four times. Depending on how advanced the glaucoma is, we generally try laser treatment before surgery.
Q: How is surgery used to treat glaucoma?
A: There are several types of surgery for glaucoma. These procedures are done in the operating room. Surgery may be a good option for patients who have side effects from eye drops they cannot tolerate, or for whom the drops are not stopping the progression of glaucoma. After surgery, some patients don’t need eye drops, while others need less than before.
A newer procedure combines cataract surgery with implanting tiny drainage tubes in the eye. The fluid goes to a collection area in the eye and is then absorbed into nearby blood vessels. This procedure has several advantages. Removing the cataract lowers pressure in the eye, so we often use this procedure even if a person’s cataracts are not fully developed. We find that a lot of people who have mild or moderate glaucoma, who have had to use drops, often no longer need drops after this procedure.
Another type of surgery, called a trabeculectomy, is generally used for more advanced cases of glaucoma. It creates a new drainage channel for fluid to leave the eye. This procedure is more invasive than the cataract procedure. Sometimes, a drainage shunt has to be placed within the eye to drain the eye better and thereby lower the pressure.