Preventing Blindness: Simple steps to detect and treat glaucoma
Every year, glaucoma robs thousands of Americans, mostly African-Americans, of their eyesight. It doesn’t have to be that way, says Kevin C. Greenidge, M.D., MPH, FACS, chairman of the Department of Ophthalmology at Long Island College Hospital in Brooklyn, N.Y. In an interview with TNJ, Dr. Greenidge gives simple steps to detect and treat this condition.
THE NETWORK JOURNAL: What is glaucoma?
DR. KEVIN GREENIDGE:
Glaucoma is excessive pressure on the optic nerve that affects your sight. There are actually several different types of glaucoma, but the most common is called open-angle glaucoma.
TNJ: How does glaucoma affect the eye?
DR. GREENIDGE: The eye is nourished by fluid flowing into it. That fluid should also leave the eye, but in glaucoma it accumulates and puts pressure on the optic nerve, affecting your vision.
TNJ: Who is most likely to develop glaucoma?
DR. GREENIDGE: Anyone can, but it’s most likely to develop in African-Americans, in whom the risk starts at age 40; people with a family history; those who are over 60; and anyone with a history of high blood pressure, diabetes or eye injury.
TNJ: Why does it affect African-Americans so early?
DR. GREENIDGE: Extensive research is ongoing, but the truth is, we just don’t know.
TNJ: How does open-angle glaucoma affect those who develop it?
DR. GREENIDGE: The most serious effect is blindness, especially for African-Americans. Again, we don’t know why. But we do know that for every Caucasian who loses sight from this disease, eight African-Americans go blind. Those who don’t go blind can lose their peripheral, or side, vision. Sometimes the loss is dramatic.
TNJ: What are the warning signs?
DR. GREENIDGE: The sad fact is that of the approximately three million Americans who suffer from open-angle glaucoma, about half of them don’t know they have it! There are no symptoms at all. Even when the peripheral vision becomes affected, many people don’t notice it. I treated one lady, a seamstress, who had lost 90 percent of her peripheral vision, but who had no trouble threading needles. Her central vision was crystal clear. She didn’t come in until she couldn’t see.
TNJ: Will my regular eye exam detect it?
DR. GREENIDGE: It might not. Anyone with risk factors should see an ophthalmologist, an eye M.D., every year, rather than the every two or three years we recommend for most of the population. And that doctor must do more than just a simple pressure check.
TNJ: Why is that?
DR. GREENIDGE: About 40 percent of patients with glaucoma will show a normal pressure reading because the fluid accumulation and the resultant pressure fluctuate. The pressure might read fine at the time it is checked. So your doctor must do a careful evaluation of the optic nerve’s appearance as well as function. If it looks suspicious, a visual field test to check its function is indicated.
TNJ: What are the treatments?
DR. GREENIDGE: The first step is prescription eyedrops. These medications work by either decreasing fluid made by the eye, or increasing the fluid flowing out. Some of the new medications can be taken once a day, which helps many individuals adhere to their regimen.
TNJ: What other treatments are there?
DR. GREENIDGE: There are two types of surgical procedures, both designed to help improve fluid drainage. First, there are quick, outpatient laser surgeries that reduce eye pressure by up to 20 percent to 25 percent in about 80 percent of patients. These are NOT the laser surgeries you hear about to fix nearsightedness. There’s also a more extensive microsurgery procedure, called a trabeculectomy, in which we use the patient’s own tissue to create new drains. Neither surgery will restore vision, but the procedures can help the patients from losing more vision. Finally, we sometimes use medication during and after the microsurgery to prevent, or at least limit, scar tissue forming on the incisions we’ve made in the eye.
TNJ: Can glaucoma be prevented?
DR. GREENIDGE: Unfortunately no. The good news is that 80 percent of the visual loss we see from glaucoma can be prevented. The key is early detection. If you don’t have a regular ophthalmologist, I urge you to look for community screening programs. Long Island College Hospital has a program in which we screen people every weekend at churches, malls—all sorts of places in the community.