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| Posted on Wednesday, February 15, 2006 |
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Glaucoma Often Diagnosed Too Late
By Wendy J. Meyeroff
THE ERICKSON TRIBUNE
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Resources for Glaucoma Information | |
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National Glaucoma Research, a program of the American Health Assistance Foundation (AHAF): 1-800-437-2423, or www.ahaf.org. AHAF’s booklet, Living with Glaucoma, has an extensive listing of resources, including eye hospitals, vision aids, and print/audio materials for the visually impaired.
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American Optometric Association: 1-800-365-2219, www.aoa.org |
“Unlike cataracts, in which the recommendation most often is that patients wait until they develop more fully, glaucoma is the exact opposite. You have to start looking for it even before there are symptoms,” says Samuel Boles, M.D.
Boles is a glaucoma-certified ophthalmologist with Omni Eye Specialists and a consulting specialist at Oak Crest, a community in Parkville, Md., built and managed by Erickson. “Glaucoma is a silent threat. By the time symptoms develop—including blurred vision and halos seen around lights—the damage to your vision has already occurred,” he says.
A Major Vision Threat
There are approximately 3 million Americans with glaucoma and 65 million cases worldwide. Every year 300,000 Americans are diagnosed with glaucoma, and one-third of them lose some portion of their vision because of it. At least 5,400 people lose their eyesight completely because of glaucoma every year. What is glaucoma? It has 10 different forms, but 95 percent of cases are what is known as open-angle glaucoma. The eye constantly makes fluid (called the aqueous humor) to stay inflated. In a healthy eye, there is a balance between how much fluid stays in the eye and how much leaves it.
In the eye with glaucoma, fluid builds up, causing intraocular pressure (IOP) to rise. This pressure eventually damages the optic nerve, the nerve fibers that carry images to the brain.
Tests for Glaucoma
There are several tests for glaucoma, and Medicare covers 80 percent of your costs. There is the visual acuity or 20/20 test where an eye professional examines how well you see near and far, and the visual field test where they check how wellyou see ahead and to the side. “For glaucoma, a very important test is the tonometry test, which checks fluid pressure inside the eye,” says Boles. Current recommendations define “normal” pressure as falling anywhere between 12 and 22 mm HG (millimeters of mercury), with most people averaging 15 to 16 mm HG.
There is one caution about pressure readings. “There is one form of glaucoma called ‘normal-tension glaucoma’ in which the diseaseexists, but the eye pressure reads normal. We don’tfully understand the cause,” Boles says.
A new diagnostic that’s helping doctors is optic nerve imaging. “It’s a major advance for earlier diagnosis of glaucoma. It gives a 3-D image of the optic nerve so we can see more clearly, if its shape is distorted. That allows us to start treatment sooner so as to minimize any damage,” Boles explains.
Treatment Advances
“Broadly speaking, there are three treatment options for fighting glaucoma: medications, laser correction, and surgery. Thanks to advances in the first two, we need to use surgery less often,” says Boles.
“Consider medications. We used to rely on drugs called beta blockers and alpha agonists. One thing that’s under-appreciated is the potential for significant side effects, especially among older people.
“They can cause congestive heart failure, asthma, and excessively low blood pressure, among other problems. More eye professionals are using a newer class of drugs called prostaglandins, eye drops which have shown minimal side effects,” says Boles.
A procedure called argon laser trabeculoplasty (ALT) used to be the main treatment for opening the fluid channels of the eye, but there is a newer version more favored by doctors: selective laser trabeculoplasty (SLT).
“With SLT, the laser targets select cells and the laser can be used at lower levels. It seems to be much safer and is allowing us to repeat the procedure many times without scarring. That’s good news because many times the channel has to be reopened within one to three years,” he says.
There are some people for whom surgery requiring an incision in the eye may be necessary. One of the newest of these procedures is a trabeculectomy which offers the advantage of allowing the patient to discontinue all medications if it succeeds. However, like all surgeries it has risks and experts suggest talking with a glaucoma specialist to find out when or if surgery is really necessary.
When Vision Does Fail
While no one wants to face irreversible vision losses, there is good news in this area, too. There are devices, and simple techniques to help you adjust.
Among your options:
- Remove obstacles you might trip over in your home, such as throw rugs and hassocks.
- Have the utility company put large-type stickers on stoves and thermostats.
- Use large font sizes on your computer.
- Use magnifiers to help you read.
There are numerous booklets and organizations that can further help you with ideas (see sidebar above).
Get Started Now
Boles urges everyone to get checked for glaucoma sooner than later. While latest indications are that those most at risk are generally over age 60, a family history of glaucoma, and African- Americans (whose risk starts as young as age 35), “I generally tell people to start getting tested annually at age 40. These are simple tests and we can prevent or at least minimize glaucoma’s damage,” says Boles.