Glaucoma: The Silent Vision Thief

his is no common burglar. This robber doesn't want cash, your phone or even a flat-screen TV. Instead, this bandit is interested in taking away one of your most precious gifts-your eyesight. This thief has a name: glaucoma. And it's the leading cause of blindness in people of African heritage. Half of those with glaucoma don't know they have the disease.

"The most important thing to know is that there are no symptoms with glaucoma," says Dr. Bret Hughes, director of glaucoma service at Kresge Eye Institute in Detroit. "If I break my arm, the pain will cause me to see a doctor. Glaucoma is not one of those diseases."

Hughes calls glaucoma "a silent condition."

Hughes, who is also an associate professor in department of ophthalmology at Wayne State University School of Medicine, notes that you may think your vision is fine, when it is actually diminishing.

"It's a slow dimming over the years," he says. "It's very subtle and not noticeable in the early stages."

Bigger risks for Blacks

Glaucoma is actually a group of diseases, all of which lead to irreversible loss of vision. Hughes notes that while there is more than one type of glaucoma, the most prevalent type in the United States is primary open-angle glaucoma, or POAG.

While the risk is universal, especially in middle age and up, certain groups are more prone to POAG-particularly in Black people. This trend was widely publicized by the "Baltimore Eye Survey" in 1991, which looked at the disease in Blacks and Whites ages 40-plus.

The verdict? POAG rates were "four to five times higher in Blacks as compared with Whites," notes a study summary from the Journal of the American Medical Association, aka JAMA.

By age 70, the numbers are startling: While one in 50 Whites have the disease, the tally is one in eight for Blacks, notes The Eye Center in Virginia, citing the Baltimore study.

Elderly people of African ancestery are also "14 to 17 times more likely to become blind than similar-aged individuals with European ancestry," the American Academy of Ophthalmology noted in 2011.

Why African-Americans are more at risk

Glaucoma has ties to genetics. According to the Glaucoma Research Foundation, your risk is 20 percent higher if someone in your family has glaucoma.

"If you have a family member who has glaucoma, it's extremely important for you to be checked," Hughes says.

The reasons for the higher rates of glaucoma and later blindness among people of African descent are unknown. Still, one thing is clear: Early diagnosis and treatment is critical in preventing vision loss.

"The only way to know if you have glaucoma is to have a comprehensive exam with your eye care provider," Hughes says. "By the time you start to complain, it's too late to improve your vision. We can only prevent further loss."

How to prevent glaucoma

To be safe and accurate, the Glaucoma Research Foundation recommends your doctor check five factors before making a glaucoma diagnosis: inner eye pressure, the shape and color of the optic nerve, complete field of vision, the angle in the eye where the iris meets the cornea, and the thickness of the cornea.

With early detection and prompt treatment, doctors say you may be able to protect your eyes against serious vision loss.

Don't let the "sneak thief" rob you or a family. Work with your eye-care professional. Make and keep regular appointments for exams. Ask questions and get the info you need to take care of yourself and your family.