Saving Your Sight: Early Detection Is Critical

by Food and Drug Administration (FDA)

Sometimes eye diseases occur with the natural aging process. Other times, they run in families, in the same way that cancer or heart disease might. Diseases and conditions such as diabetes and high blood pressure also increase the risk for eye problems. The leading causes of irreversible blindness — glaucoma, diabetic retinopathy, and macular degeneration — tend to come on silently, without pain or other symptoms in the earliest stages. The later an eye problem is diagnosed, the harder it becomes to treat. In some cases, any vision that has slipped away may be gone forever.

Experts say that skipping regular and thorough eye exams is chief among the barriers to early detection. It's important to have your eyes regularly checked through dilated pupils so doctors can get a good three-dimensional view of the optic nerve and retina. For a dilated exam, an eye specialist places drops in the eye to enlarge the pupils. "Without dilating the eye, it's like looking inside a room through a keyhole instead of an open door," according to George Blankenship, M.D., immediate past president of the American Academy of Ophthalmology (AAO).

Also problematic is the tendency to ignore symptoms when they do present themselves, says Lee R. Duffner, M.D., an ophthalmologist in Hollywood, Fla. "It's not uncommon to see patients who say they've been having eye problems for a whole year before coming in to get checked — usually because of a spouse or other relative who encouraged them to come in."

Here's a look at four eye diseases you can't afford to miss.

Glaucoma

The Problem:

It's not known why, but people with glaucoma typically experience an imbalance in eye fluid production and drainage. Fluid that normally flows in and out of the eye drains too slowly. As that fluid builds up, pressure in the eyeball increases and becomes abnormally high, a condition that can damage the optic nerve, the retina, or other parts of the eye.

It's important to note that there are also patients with glaucoma who actually have what would be considered normal eye pressure, says Sheryl Berman, M.D., a medical officer in the Food and Drug Administration's division of ophthalmic and ear, nose, and throat devices. "This is why it is so critical to have dilated examinations, since routine pressure screening would miss the diagnosis of glaucoma in these eyes." For these people, there are other factors at play that may lead to optic nerve damage.

If glaucoma is left untreated, blindness is likely. The most common form of glaucoma is primary open-angle glaucoma, also known as chronic glaucoma. Nearly 3 million Americans have glaucoma, according to the National Eye Institute (NEI), and about half do not know it. That's because glaucoma is a silent stealer of sight; there are usually no symptoms in the early stages. As the disease progresses, people with glaucoma may notice their side (peripheral) vision failing. But by this time, the disease is usually quite advanced and the damage is irreversible. Once vision is lost, it can't be restored. Glaucoma usually affects both eyes, one shortly after the other.

Ida Miggins, 52, a computer specialist from Takoma Park, Md., says she learned she had glaucoma three years ago by chance. She hadn't had an eye exam since childhood and hadn't noticed any vision problems. "I was actually taking my mother to her eye appointment, and the doctor suggested that I be checked too," says Miggins. The doctor diagnosed glaucoma in both eyes.

Risk Factors:

Early detection is the best way to control glaucoma and prevent major vision loss. Elevated pressure in the eye is the major risk factor for glaucoma. Other risk factors associated with the disease include having high blood pressure, diabetes, and certain diseases that affect blood vessels. A family history of the disease, aging, and African ancestry also increase your risk for glaucoma.

Studies have shown that for unknown reasons, glaucoma presents at an earlier age in blacks, is five times more likely to occur in blacks than in whites, and is about four times more likely to cause blindness in blacks than whites.

Miggins, who is black, says she had heard of glaucoma. "But I didn't have a clue what it was, nor did I think I was at risk for it because it doesn't run in my family."

If you are in any of the high-risk groups for glaucoma — everyone over age 60, those with a family history of the disease, and blacks over age 40 — you should get a complete eye exam at least every two years.

Treatment:

Though glaucoma is not curable, there are treatments that successfully lower pressure in the eye. The first line of treatment is drugs, and whether you're prescribed eye drops or pills, taking your drugs as prescribed is critical.

The development of several classes of medications to reduce pressure in the eye has allowed for more effective treatment over time, says Wiley Chambers, M.D., deputy director of the FDA's division of anti-inflammatory, analgesic and ophthalmic drug products. For now, glaucoma medications only tackle eye pressure, says Chambers. "We're looking for treatments that can also protect the optic nerve."

Miggins says the first medication she took caused bleeding gums and eye pain. Some side effects may lessen over time, but be sure to report them to your doctor because it could be that the drug or dose needs to be changed.

In March 2001, the FDA approved two new drugs to treat elevated eye pressure, Lumigan (bimatoprost ophthalmic solution), marketed by Allergan Inc. of Irvine, Calif., and Travatan (travoprost ophthalmic solution), marketed by Alcon Laboratories Inc. of Fort Worth, Texas. These medications provide alternatives for people who are intolerant or unresponsive to other drugs and who otherwise may need surgery. Potential side effects of these two drugs include gradual darkening of eye color and darkening of eyelid skin.

When glaucoma can't be controlled with medication, doctors may turn to laser surgery in which a focused beam of light creates openings in the part of the eye where fluid drains to make draining easier. The next line of treatment is a surgical procedure called trabeculectomy, in which a small opening is made in the front chamber of the eye to make a new pathway from which fluid can drain. Even with surgery, many patients who have glaucoma still need medication.

For those with very advanced disease, or when conventional medical and surgical treatments have failed to control the disease, glaucoma may be treated with a drainage device, a little plastic tube. These devices are surgically implanted to create a new drainage pathway. In July 2001, the FDA approved the AquaFlow Collagen Glaucoma Drainage Device from STAAR Surgical Company in Monrovia, Calif., to manage open-angle glaucoma. A small cylinder made of collagen is implanted in the eye to absorb excess fluid. The device is designed to maintain a space under the white part of the eye, and it slowly dissolves in the eye until it's completely absorbed within nine months, leaving behind a drainage route for the fluid.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.