Are you at risk for glaucoma?

Glaucoma is an eye disease that causes loss of vision — usually side vision — by damaging the optic nerve, which sends information from your eyes to your brain. Some forms of glaucoma don’t have any symptoms, so you might have it even if you don’t have trouble seeing or feel any pain.

That’s why glaucoma is often called “the sneak thief of sight.”

Fortunately, you can prevent vision loss by finding and treating problems early. Medicare covers a glaucoma test once every 12 months for people at high risk for glaucoma, including people who answer “yes” to one or more of these questions:

>> Do you have diabetes?

>> Do you have a family history of glaucoma?

>> Are you African-American and 50 or older?

>> Are you Hispanic-American and 65 or older?

Glaucoma tests are covered under Medicare Part B (medical insurance). An eye doctor who’s legally allowed to do this test in your state must do or supervise the screening.

How much will the test cost you? You pay 20 percent of the Medicare-approved amount, and the Part B deductible ($183 this year) applies. If the test is done in a hospital outpatient setting, you also pay a copayment.

To find out how much your specific test will cost, talk to your doctor or other health care provider. The specific amount you’ll owe could depend on several things, such as:

>> Other insurance you might have.

>> How much your doctor charges.

>> Whether your doctor accepts Medicare payment as full payment.

>> The type of facility where you’re tested.

>> The location where you’re tested.

There is no cure for glaucoma. Vision lost from the disease cannot be restored.

Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. If glaucoma remains untreated, people can miss objects to the side and out of the corner of their eye. They seem to be looking through a tunnel. Over time, straight-ahead (central) vision can decrease until no vision remains.

Immediate treatment for early-stage, open-angle glaucoma can delay progression of the disease. That’s why early diagnosis is very important.

Glaucoma treatments include medicines, laser trabeculoplasty, conventional surgery or a combination of these. While these treatments might save remaining vision, they do not improve sight already lost from glaucoma.

Glaucoma is detected through a comprehensive dilated eye exam that includes the following:

>> Visual acuity test. This eye-chart test measures how well you see at various distances.

>> Visual field test. This test measures your peripheral vision. It helps your eye care professional tell whether you have lost peripheral vision, a sign of glaucoma.

>> Dilated eye exam. In this exam, drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision might remain blurred for several hours.

Tonometry measures pressure inside the eye by using an instrument called a tonometer. A tonometer can detect glaucoma. Numbing drops may be applied to your eye for this test.

Pachymetry is the measurement of the thickness of your cornea. Your eye care professional applies a numbing drop to your eye and uses an ultrasonic wave instrument to measure your cornea’s thickness.

For more information on glaucoma, go to bit.ly/1lZV2T8.

Greg Dill is Medicare’s regional administrator for Arizona, California, Nevada, Hawaii, and the Pacific Territories. You can always get answers to your Medicare questions by calling 1-800-MEDICARE (1-800-633-4227).