- The Washington Times - Tuesday, August 7, 2001

Edith Marks once thought she saw a floating horse's head while strolling through Central Park. She actually was looking at a baby carriage. Mrs. Marks has glaucoma, a disease marked in most cases by a blockage of the fluid, the aqueous humor, that normally drains from the front part of the eye. Trapped but constantly replenished by the gland that produces it, the welling fluid builds up pressure against the shell of the eyeball and particularly the optic nerve, causing compression of the nerve cells and their death and, eventually, permanent loss of some vision.
So what Mrs. Marks sees is not always what she gets.
"If I'm not familiar with an object, it may look like something it's not," says the 77-year-old writer, who has been managing her glaucoma for 25 years and even wrote a book about it, "Coping With Glaucoma: A Guide to Living With Glaucoma for You and Your Family" (Avery Publishing Group, 1997, $13.95 paper).
Mrs. Marks is not alone. About 3 million Americans have glaucoma, and another 100,000 develop the disease each year, according to a study by Prevent Blindness America, a national nonprofit organization devoted to education about the eyes. Half of them don't know they have it.
Even worse, the standard pressure test used to check for glaucoma, air tonometry, often called the "puff" test, cannot identify about half of all glaucoma cases, says Dr. Harry Quigley, director of the Glaucoma Service at the Wilmer Eye Institute at Baltimore's Johns Hopkins Hospital. Because the two main types of glaucoma that occur in American adults can happen at normal eye pressures, a definitive diagnosis requires that an ophthalmologist or optometrist examine the back of the eye and test a patient's peripheral vision.
"The air puff is not anything useful," says Dr. Robert Ritch, founder of the Glaucoma Foundation, a leading nonprofit organization founded in 1984 and based in New York City.
Glaucoma is frequently associated with old age, but anyone at any age can develop the disease. Blacks, Hispanics and, to a lesser extent, Asians, are especially susceptible.

Glaucoma is actually several diseases under one name. The two main forms of glaucoma that afflict American adults are open-angle (or chronic) glaucoma and closed-angle (or acute) glaucoma, Dr. Quigley says.
The "angle" in question is the place where the iris and cornea meet, where fluid drains from the eye through a tiny, spongy tissue called the trabecular meshwork. In most people, this angle is about 45 degrees.
Primary open-angle glaucoma is the most common in the United States; about 1 percent of all Americans suffer from it. Not only is this variant painless, but no symptoms are visible. Because the intraocular pressure (IOP) rises slowly, the cornea adapts to the rise in pressure without swelling against the iris, thus averting any telltale narrowing of the angle. Not even the trabecular meshwork looks abnormal although, in fact, it is not doing its job.
No one knows why in this case the drainage system fails to work. One theory being studied holds that with age, people lose cells from the system. Others assume structural defects in the meshwork or problems with the body's enzymes.
A subset of open-angle glaucoma is known as normal-tension or low-tension glaucoma. It is thought to be related to poor blood flow to the optic nerve. In it, even though the intraocular pressure remains statistically normal, the optic nerve is damaged progressively. This suggests that people with this condition must sustain a lower-than-normal pressure to keep their sight.
Another variant of open-angle glaucoma, pigmentary glaucoma, afflicts mainly the myopic, or nearsighted. It tends to develop more frequently in men than in women and begins in young adulthood. In it, the concave-shaped iris characteristic of myopia creates an unusually wide angle that causes the pigment layer of the eye to rub on the lens, shedding pigment into the drainage system and clogging it.
Another type of shedding of a whitish material that builds up on the lens can lead to either open-angle or closed-angle glaucoma. It occurs with age and mainly among people of European descent.
Secondary glaucoma, found in children, is extremely rare, occurring in one out of 10,000 glaucoma cases, Dr. Quigley says. It usually happens when a child gets "whacked in the eye," he says.
Because open-angle glaucoma can occur at normal and high pressures, not all cases can be diagnosed by conventional tests. What all cases have in common is that the back portion of the eye wall collapses, and the supportive tissues give way. The consequence: dead optic nerves. This can happen because a person has either high eye pressure or weak supportive tissues.
Dead cells can no longer do their job — sending the brain messages about what the eye sees. Blind spots begin to appear in a person's peripheral vision. In later stages of the disease, the spots spread to the central vision field.

Closed-angle glaucoma affects nearly a half-million Americans. Thought to be inherited, it is most common in the hyperopic or farsighted, people in whom the eye's front chamber (that bounded by the cornea, iris, pupil and lens) is smaller than average, a condition that means the angle where cornea and iris meet is narrowed to begin with. Asians are five times more likely to develop closed-angle glaucoma than open-angle glaucoma, Dr. Quigley says.
As people age, the lens grows larger, narrowing the angle even more and causing fluid pressure to build up behind the iris. The iris swells forward, blocking drainage, a situation the Glaucoma Foundation in its educational materials likens to putting a stopper over the drain of a sink.
In about 20 percent of closed-angle glaucoma cases, the result is a sudden rise in pressure that produces intense pain that may cause nausea and vomiting. Attacks occur within a few hours and are incredibly painful.
"It's an H-bomb-like attack, and it feels like the worse pain in your life," Dr. Quigley says. The eye becomes red, and the victim may have blurred vision. An acute attack is an emergency. If treatment is delayed, eyesight can be destroyed permanently, Dr. Ritch says.
Not all closed-angle glaucoma sufferers will experience an acute attack. Some may develop what is called chronic closed-angle glaucoma. In this case, the iris gradually closes over the drain, causing no overt symptoms. When this occurs, scars form slowly between the iris and the drain, and the fluid pressure will not rise until enough scar tissue has formed to cover the drainage area.

When she found out she had glaucoma, Edith Marks considered herself far too young. She was 52.
"I did a lot of denying it. I was too busy at work," says the former special-education teacher. "When you're in your 50s, you still have your life ahead of you. You don't want to bothered by an illness."
Mrs. Marks has open-angle glaucoma. For a while, she didn't know she had it.
"The loss of vision is so gradual that you're not aware of what you don't see," she says. "I'm never aware until my husband points something out."
She believes she developed the disease because of the prescribed steroid eyedrops she used after undergoing laser surgery to repair retinal tears. Prolonged steroid use is a risk factor for developing glaucoma.
Weeks after the surgery, her doctor took her eye pressure, which rang high in her left eye.
Her doctor prescribed eyedrops to reduce the pressure.
There are three treatments for glaucoma: eyedrops, laser surgery and surgery, usually done in that order. However, patients should choose what treatments are best for them, Dr. Quigley says. All treatments are designed to reduce eye pressure by 30 percent, he says, even if a person's eye pressure is high.
When use correctly, eyedrops are just as effective as laser therapy and surgery, Dr. Quigley says. However, many people have problems administering them regularly and correctly. The most common and effective eyedrop used to treat glaucoma is Xalatan, he says.
Mrs. Marks used eyedrops for two years. Unfortunately, her pressure began to rise again. She opted for lasery surgery.
Laser surgery takes about 10 to 20 minutes. It is a painless procedure and can be performed on an outpatient basis. In the procedure, a laser beam is directed upon the eye's drain. The laser's heat shrinks some parts of the drain. This shrinkage forces other parts of the drain to stretch, allowing for fluid drainage.
Dr. Howard S. Weiss, an ophthalmologist with Washington Eye Physicians and Surgeons in Bethesda, says the benefit of laser surgery is that there is no bleeding or infection. However, not everyone can be treated with a laser.
"It's not the end-all, cure-all," he says.
Patients can get back to their routines a few hours after surgery. This procedure is effective in 85 percent of all patients, Dr. Quigley says.
Mrs. Marks was not part of that lucky 85 percent. Two years later, her pressure began to rise again.
She opted for surgery, which can be done on an outpatient basis or with a short hospital stay. With this procedure, a small part of the eye's drain is removed. This allows fluid to drain more freely and reduces eye pressure. A downside of the surgery is that about one-third of patients develop cataracts within five years of the operation and about 15 percent require additional surgery, according to the Glaucoma Foundation.
After this procedure, Mrs. Marks developed glaucoma in her right eye and went through the whole process — eyedrops, laser surgery and surgery — again.
Since then, she has been battling to keep down the pressure in both eyes. The right eye has stabilized, and she has 20-30 vision there. She doesn't know yet about the left.
To combat her glaucoma, she plays on her past experiences to develop keen perceptive vision.
"I will see something and immediately connect it with something I know," she says. "I use past experience to see."
She often practices seeing while waiting online or for buses.
"When I see a building for the first time, I try to look at all corners, the brickwork and the architecture," she says. "It exercises the eye."

Though glaucoma can affect any person of any age, some people are more prone to developing it than others. At-risk groups include people with a family history of glaucoma, diabetics, adults older than 45 and people who have experienced previous eye injuries. People who are extremely nearsighted or farsighted, do not get regular eye exams and have used steroids and cortisone for long periods of times also are in danger.
Blacks are extremely vulnerable to glaucoma.
"No single population is more at risk than people of African descent: One in 13 has the disease, and glaucoma occurs four to six times more often than among Caucasians," says John Corwin, executive director of the Glaucoma Foundation.
Blacks are so much at risk of developing the disease that the Glaucoma Foundation provides free testing in Harlem, as do several Harlem community groups. The Wilmer Eye Institute gives free tests in church basements and community centers in primarily black neighborhoods.
Dr. Quigley recommends glaucoma tests for blacks older than 30 and whites older than 40.
Testing must be done to look at the back of the eye. If a person has glaucoma, the back portion will be pushed outward. The back portion can be viewed easily by dilating the pupils, Dr. Quigley says. An experienced doctor can detect most glaucoma cases with this examination. However, ophthalmologists give the most thorough exams for glaucoma, involving a visual-field test that checks a person's side vision, and a blue-slit lamp which snaps a picture of the optic nerve.
People need to decide on their own whether to see an optometrist or an ophthalmologist for a glaucoma test, Dr. Quigley says. "Americans need to make their own judgment. If they feel most comfortable with an optometrist, that's fine."
An optometrist, whose main job is prescribing eyeglasses and giving routine eye exams, cannot give visual-field or blue-slit tests, but they can check for glaucoma by dilating the pupils. Optometrists can prescribe eyedrops but cannot perform any type of surgery.
This article was prepared with the help of educational materials from the Glaucoma Foundation. For further information see their website at www.glaucoma-foundation.org.

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