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Eyes Aglow: The Rev. William Maring, a Jesuit priest, is tested for glaucoma with an applanation tonometer at Dr. John Sullivan's office in San Jose.
Photograph by Paul Myers
Glaucoma affects millions and can cause vision loss
By Rita Baum
Part of this series on age-related vision changes was written onboard a cruise ship while traveling through the Inland Passage and Gulf of Alaska. People all around could be heard marveling at the sights: the majesty of wide glaciers cascading down mountain valleys, the whales doing a ballet as they lunged for food, the sea lions lolling on the rocks. A friendly passenger commented to those within earshot how lucky he was to be able to see it all.
Fifteen years earlier, the man had unexpectedly found that he had a serious case of glaucoma, discovered during a doctor's visit to remove a cinder from his eye. A former firefighter, he had not had an eye exam since childhood. Luckily, the doctor started him on medication before the condition advanced further, and his glaucoma has been controlled with light medication ever since. He described a less fortunate friend with a more advanced case of glaucoma that required medication four times stronger than his--because it was detected at a later stage. As is often the case with glaucoma, his friend had experienced no symptoms in the early stages of the disease and believed he had no reason to see an eye doctor until the condition had greatly advanced.
The traveler is a strong proponent of regular eye exams after age 65, and with good reason. He knows that the incidence of vision problems increases with age and that glaucoma is the leading cause of adult blindness, affecting 100 million people worldwide and more than 2 million Americans. Glaucoma robs sight slowly, surely and irreversibly--generally without any symptoms--and causes permanent damage if left untreated. Fortunately, progression of the disease and blindness can be prevented with early diagnosis and treatment.
Three percent of Americans over age 70 have glaucoma, but the disease can affect people of any age, sex and race. At higher risk are those with a family history of glaucoma, nearsighted persons, African Americans and persons who have high blood pressure. Risk is higher for Caucasians over the age of 50 years of age and African Americans over the age of 35. Diabetes and trauma to the eye are also risk factors, and there is some evidence that heart disease, poor circulation in the legs and feet, and hardening of the arteries also contribute to risk. Dr. John Sullivan of the Eye Medical Clinic in San Jose says research has shown that regular exercise alone can reduce intraocular pressure in some glaucoma patients by 20 percent.
Resources: Organizations that provide information on glaucoma.
Half of the 3 million Americans that have glaucoma are not aware of it because there are no noticeable symptoms in the early stages. Glaucoma may go undetected for years.
Glaucoma is a disease of the optic nerve, which makes sight possible by communicating visual information to the brain. It generally progresses slowly and without notice, damaging the eyes over several months or years, causing gradual and irreversible vision loss. Side or peripheral vision is lost first, leaving central vision pretty much intact. If treated in the early stages, progressive vision loss may be stopped in its tracks. If not treated, peripheral vision loss progresses, gradually narrowing the field of vision, until central vision is affected. The affected person may not notice the problem until this later stage. By then driving and other activities may need to be restricted. If treatment is still not received at this later stage, then vision can be completely lost.
Because vision loss from glaucoma can never be restored, it is critical to detect and treat it before serious damage to the optic nerve occurs. Early detection is the key to successful treatment. Once the disease has progressed to the point where symptoms are present (blurred vision, halos around lights, eye pain and redness), immediate treatment is necessary.
Glaucoma is most often associated with high pressure inside the eye. Fluids are important to the functioning of all the body's tissues and organs, and the eyes are no exception. A normal eye will continuously produce and drain fluid, but if fluid does not drain properly, pressure in the eye increases, slowly damaging the optic nerve and retina. Some people are able to tolerate high eye pressure without developing glaucoma or experiencing damage to the optic nerve, while others may develop glaucoma without any evidence of increased pressure inside the eye.
Ophthalmologists conduct three types of tests to screen for glaucoma and later to monitor the progress of the disease. A test for intraocular pressure is done; peripheral or side vision is measured; and the health of the optic nerve is checked by looking inside the eye. A healthy nerve has a small concave hole in the center. As glaucoma progresses, this hole enlarges, eliminating healthy tissue in the process. A doctor can check the health of the nerve and the progression of the disease by inspecting the appearance of the nerve two or three times a year. A general practitioner or optometrist can also do an intraocular pressure test for glaucoma to detect the earliest signs.
The most common type of glaucoma is open-angle glaucoma, which typically causes no symptoms until damage and vision loss occurs. A less common type of glaucoma is narrow-angle glaucoma, more often found in persons of Chinese and Vietnamese descent, though it can affect people of any race. This type may cause symptoms of sudden pain, redness, blurred vision and colored haloes around lights. Failure to treat narrow angle glaucoma immediately when these symptoms occur can cause permanent vision loss.
Treatment for open-angle glaucoma generally begins with eye drops that are designed to lower the pressure in the eye by decreasing the amount of fluid produced, or to increase the amount of fluid drained from the eye. Oral medications are also available to lower the eye pressure. A less common way of treating glaucoma is with a laser designed to increase the amount of fluid drained from the eye, thereby lowering the pressure. Treatment may also include microsurgery, which creates a small drainage hole in the eye.
Regardless of the type of treatment, a patient with open-angle glaucoma must continue to be monitored by an ophthalmologist several times a year to make sure that the disease has been stabilized and that additional vision loss does not occur.
Glaucoma checks should be done once after age 19, three times after age of 35, every two years after age 50 and yearly after age 65--more frequently if there is a family history of glaucoma or for persons with diabetes or high blood pressure.
As the Alaska cruise traveler learned, tests can reveal damage long before vision loss occurs, and the key to early detection and treatment is regular eye examinations, ensuring that our precious sight is never lost or compromised.
This article is not intended to provide medical advice, which should be obtained directly from a physician.
Rita Baum has a master's degree in gerontology and has worked in the field of aging for more than 20 years.
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Willow Glen, California Since 1992
