Silent Sight Stealer
At this moment, experts estimate that several million Americans are on the road to blindness and don't know it. The disease that wreaks this visual havoc is glaucoma and it has no symptoms -- at first. Eventually, patients begin to lose peripheral vision, but by this time, damage is already considerable and permanent. Everyone over age 40 needs to be aware of the disease to prevent suffering needless loss of sight. How can you reduce your risk? Ophthalmologist Gregory K. Harmon, MD, is director of glaucoma services at the New York Presbyterian Hospital-Weill Cornell Medical Center and coauthor of What Your Doctor May Not Tell You about Glaucoma -- The Essential Treatments and Advances That Could Save Your Sight (Warner Books). I spoke with him about the latest findings regarding glaucoma. Dr. Harmon told us that the condition isn't a single disease, but rather several different ones that have a common denominator -- they damage the optic nerve (a bundle of fibers in the back of the eye). By far the most common type of glaucoma in the western world -- and the focus of our discussion -- is one called open-angle glaucoma with its slow, early asymptomatic progression. (The other principal type is narrow-angle glaucoma -- which is most likely to affect Asians and has an acute, dramatic onset.) African Americans are much more prone to glaucoma than are whites -- their risk of it is four to six times higher, says Dr. Harmon. And, it appears that Hispanics probably have the same vulnerability as African Americans.
EYES UNDER PRESSURE
Until recently, doctors believed that the common factor for all conditions leading to glaucoma was pressure from a build-up of fluid in the eyeball. They have now discovered that people with a normal pressure reading can still have the disease -- a condition called "normal-tension glaucoma." This makes the old-fashioned eye pressure test, routinely administered to patients after age 40, insufficient for diagnosis. Rather, the best way to diagnose glaucoma is to have an optometrist measure eye pressure (tonometry) and examine the optic nerve to see if there is nerve damage.
The most important risk factor for glaucoma is pressure in the eye, says Dr. Harmon. However, you can have elevated eye pressure and not have glaucoma (a condition called ocular hypertension.) Other risks include...
Being 45 or older (although even babies can have the disease).
Having a family history of the disease.
Being substantially nearsighted -- farsighted folks are more vulnerable to narrow-angle glaucoma.
Having high or low blood pressure.
Having experienced trauma to the eye.
Use of corticosteroids, such as prednisone, whether taken internally, inhaled or used topically in the eyes.
A note about steroid use: The degree of risk concerning steroid use has to do with the strength of the medication and duration of use. Dr. Harmon says that, generally, if steroids were going to increase eye pressure, it would show up right away. Contributing editor Andrew L. Rubman, ND, reminds people that long-term use of steroids can also sometimes increase risk of glaucoma.
Doctors also evaluate the thickness of the cornea in glaucoma exams because people with thin central corneas are at much greater risk than others.
The goal of treatment is to reduce eye pressure, including in those patients with normal pressure glaucoma. Even in people with normal pressure, reducing it further prevents disease progression just as it does for patients with elevated pressure. Eye drops -- either to reduce the fluid in the eyeball or improve the efficiency of its drainage -- are the first line of treatment. The side effects of the most commonly used drops are few -- lashes get longer and thicker and blue-green eyes may turn brown -- and patients generally use drops for life. However, drops are not effective enough for everyone, in which case the next step is laser surgery. There is a new laser, Dr. Harmon explains, that creates a small amount of inflammation within the eye's drainage system. This, in turn, causes macrophages to come into the eye's drain and chomp up the debris inside the drain, a sort of Liquid Plumber effect, and leave it flowing more smoothly. There doesn't appear to be a downside to this surgery, and it can be performed multiple times without any known harm as of now. Patients generally continue using drops after laser, and the surgery allows much better success for the drops. When all else fails, the last measure is to have traditional surgery that creates a new drain. Whatever the treatment, all patients require regular monitoring to be sure the glaucoma doesn't begin to progress once again. Should that happen, more aggressive treatment is called for (or in the case of post-surgery patients, a return to drops).
NO PREVENTION -- RISK REDUCTION
Traditional medicine can not prevent glaucoma, says Dr. Harmon, but there are definitely ways to lower your risk of vision loss. He says that the healthier you are, the better your chances of avoiding it. In particular, he recommends regular aerobic exercise -- studies have shown it lowers eye pressure -- and eating foods that contain lots of antioxidants, such as green leafy vegetables and brightly colored fruits. It is critical to be checked annually. Glaucoma screening can be done by either an optometrist or an ophthalmologist. Should an optometrist find a problem, the patient is referred to the ophthalmologist for medical treatment.