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Battling glaucoma
How to prevent vision loss, plus signs, symptoms and treatment


By ROCHELLE MELANDER

September 2016

Dr. Sarwat Salim teaching glaucoma surgery in El Salvador

 

Glaucoma is one of the leading causes of blindness worldwide, and in the United States, it ranks as the chief cause of irreversible blindness in African-American adults. "Glaucoma is a progressive eye disease that can damage the optic nerve," says Dr. Sarwat Salim, professor of ophthalmology and chief of glaucoma service at the Medical College of Wisconsin. "Approximately 3 million people are afflicted with glaucoma in the U.S., and about 50 percent of these individuals may not even know that they have the disease because of its asymptomatic nature."

The optic nerve is a bundle of nerve fibers that relay information from the eyes to the brain to form the images we see. "Most often, optic nerve damage is caused by increased pressure in the eye, known as intraocular pressure," explains Salim. A clear fluid flows in and out of the anterior chamber, a space in the front of the eye, nourishing the eye tissues. The fluid leaves this chamber through a drainage area. In people with open-angle glaucoma, the fluid passes too slowly. When it builds up, the increased pressure can damage the optic nerve.

Glaucoma is actually a group of diseases. The two major categories are open-angle glaucoma and closed-angle glaucoma. Other types include secondary glaucoma and congenital/childhood glaucoma. In the U.S., the most common type of glaucoma is open-angle glaucoma. Unfortunately, because the increase in pressure happens slowly, glaucoma is usually painless and can remain undetected until the patient experiences vision loss. Without treatment, people with open-angle glaucoma lose their peripheral or side vision first and may lose their central vision too. "In closed-angle glaucoma, the increase in intraocular pressure is high and sudden. It presents with acute and severe pain in the eye," Salim says. "These patients often experience decreased vision, rainbow-like halos around lights, nausea or vomiting." Closed-angle glaucoma constitutes a medical

emergency, and patients should seek immediate help.

Glaucoma cannot be prevented or cured, but it can be controlled to prevent vision loss. Early detection is crucial. Several large studies show increased eye pressure as a key risk factor. Salim points to several other risk factors, including "advancing age, family history of glaucoma, African or Latino descent, severe myopia or nearsightedness, and systemic diseases such as hypertension (high blood pressure) or diabetes."

"Physical injury to the eye can also cause glaucoma," she continues. "Long-term use of steroids (either drops or pills) can also increase intraocular pressure." Thankfully, glaucoma can be detected through a simple set of tests in an ophthalmologist’s office. While all ophthalmologists specialize in medical and surgical eye problems, Salim recommends choosing a physician who has completed extra training in glaucoma if you’re at increased risk for the disease.

The American Academy of Ophthal-mology recommends a complete eye exam by age 40 — or earlier for those at increased risk. Salim notes that the "important elements of the examination include a visual acuity test, tonometry to measure intraocular pressure, gonioscopy to assess if the drainage angle is open or closed, slit lamp examination to assess the anterior segment of the eye, use of special lenses to examine the optic nerve and posterior segment of the eye, and a visual field

test to assess the loss of peripheral or

central vision."

Treatment for glaucoma works to reduce intraocular pressure and includes both medical and surgical options. "For open-angle glaucoma, medical therapy is initiated with eye drops," Salim says. "If medical therapy fails, laser can be performed to open the channels where the fluid flows out. When both medical therapy and laser treatment don’t work, incisional surgery in the operating room is necessary." m

 







 


This story ran in the September 2016 issue of: