Few symptoms, no cure

Glaucoma is a leading cause of blindness

When most people go to an eye doctor, they have the pressure in their eyes checked and pupils dilated so the back of the eye can be more easily viewed. These tests are conducted to check for glaucoma, which is a leading cause of blindness in the United States, with damage that is irreversible.

According to the Glaucoma Research Foundation, as much as 40 percent of vision can be lost without a person noticing before it is too late.

“Vision loss happens very slowly over time, so that’s why you wouldn’t notice it on your own, and say, if a patch of sight is gone in one eye and not in the other, that eye without the vision loss will compensate,” said Dr. Cynthia Ragland of C Eye Care in Marshalltown. “If not treated, you can end up with tunnel vision (the loss of peripheral vision which leads to a constricted circular tunnel-like field of vision).”

Over three million people in the United States have glaucoma, with the National Eye Institute estimating this figure will reach 4.2 million by 2030 — a 58 percent increase. Worldwide rates of people living with the disease currently surpass 60 million.

Glaucoma occurs when there is damage to the optic nerve. In many cases, the nerve damage is linked to increased pressure in the eye. This elevation happens when a buildup of fluid, known as aqueous humor, occurs caused by either overproduction of the fluid or improper drainage.

“Years ago, we used to think you had to have high eye pressure to have glaucoma, but that is not always the case,” she said. “You can develop normal-tension glaucoma.”

Ragland said the most common type of glaucoma is primary open-angle glaucoma (POAG).

“Acute angle-closure glaucoma is a whole different ball of wax, and people with that type could have sudden symptoms and problems,” she said.

People at risk for developing glaucoma include those over age 60, a family history of the disease, diabetics, and those who are severely nearsighted. People of African, Asian and Hispanic descent are also at an increased risk. African-Americans are 3 to 4 times more likely to develop glaucoma over Caucasians.

Ragland said she recommends that school-aged children get their eyes checked annually. Adults under 60 with healthy eyes should have eye exams every two years.

“When you are age 60 or older, you should have your eyes checked every year,” she said.

While there is no cure for glaucoma, treatment is available to slow its progression.

“We can prescribe eye drops that lower the eye pressure, and if the drops don’t do what we want them to, there are surgical procedures,” she added. “Doing optic nerve imaging [during an eye exam] gives us photos we can have that give us a baseline to see changes in the optic nerve in the future.”

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Contact Sara Jordan-Heintz at 641-753-6611 or sjordan@timesrepublican.com