Glaucoma –– an eye disease that can cause blindness –– has become one of the hottest fields in genetic research aimed at identifying and treating people most at risk, including Latinos and African-Americans.
But none of the fanciest experiments can help if you fail to get regular eye exams, including eye dilation, which is the procedure in which the doctor gives you eye drops that cause your pupils to widen so he or she can get a better view of the back of your eye.
That’s because glaucoma –– caused by sensitivity to pressure in the eyeball –– has no noticeable symptoms until it’s in an advanced stage: No pain, no eye redness, no blurry vision, and, in many cases, a loss of peripheral vision so gradual it goes unnoticed.
“There’s nothing to be on the lookout for in the early stages,” said Dr. Ahmad Aref, associate professor of ophthalmology at the University of Illinois at Chicago College of Medicine.
The risk of getting glaucoma increases as people age; it starts when the fluid inside the eye passes too slowly out of the eye’s drainage system, and the buildup of pressure kills the nerve cells that send signals to the visual cortex in the brain. It’s like a backed-up sink that can’t drain properly.
Glaucoma that goes untreated damages the optic nerve, making it the most common reason for irreversible vision loss in the United States.
Everyone should get a complete eye exam by the age of 40, Chicago-area doctors say. And you should get an exam every year if you’re 60 or older or have even a single risk factor, such as if a family member has had glaucoma; if you have diabetes or taken steroids for a long period, or if you’ve had any trauma to your eyes, no matter how long ago, said Dr. Thasarat Vajaranant, associate professor of ophthalmology at UIC College of Medicine.
Though no one yet knows why, African-Americans may have two to five times higher risk of glaucoma than Caucasians, and Latinos could be at twice the risk, according to the Los Angeles Latino Eye Study (LALES), funded by the National Eye Institute. Some researchers believe the differing risks are partly caused by people’s ethnic-based tendencies to have thinner or thicker corneas.
A thinner cornea may indicate a less protective structure around the optic nerve, said Loyola Medicine ophthalmologist Dr. Meenakshi Chaku, who specializes in glaucoma.
Glaucoma sufferer Gloria Bolton, a retired K-12 science instruction supervisor and science and math teacher, is still driving at age 71, thanks to her eye doctors and her own vigilance.
“I’m near-sighted, so I always had regular eye exams,” said Bolton, a Gary native who now lives in Highland, Ind., and whose mother also had glaucoma.
“After one of the exams, the doctor said, ‘You really need to go to a specialist [because of the buildup of pressure the doctor discovered in her eye.]'”
Bolton followed her doctor’s advice, leading to a long journey that included having an allergic reaction to her first eye-drop medicine, to having unsuccessful laser eye treatments, to getting a drain implanted in her right eye that failed, and, finally, undergoing two minimally invasive eye surgeries, including getting a new eye-pressure drainage device at the University of Illinois at Chicago.
Bolton says she has stayed positive because she caught her glaucoma in time, and now has 20/20 vision in one eye.
“I’m blessed. All I need are readers [reading glasses],” said Bolton, who earned her undergraduate degree in elementary education at Indiana University and her master’s degree at the University of Memphis. She also studied for her Ph.D. in Memphis, where she spent most of her career before returning to Northwest Indiana to be near her family.
“You must make your (eye exam) appointments and take your eye-drops diligently,” she said, noting that, at one point, she had to set alarms to remind her which eye-drops to take at which time of day. “If you are going to save your sight, you have to do what the doctors ask you to do.”
Meanwhile, remedies to treat glaucoma are racing ahead.
The U.S. Food and Drug Administration just last year approved two new eye-drops – Rhopressa, which helps people who have glaucoma through a novel action mechanism and is taken only once a day, and Vyzulta, which increases fluid drainage from the eye through two separate pathways.
New, less-invasive laser and pressure-reducing surgeries with fewer side effects than those of years ago are more widely available, said Dr. Varun Malhotra, assistant professor of ophthalmology at the University of Chicago.
The newer surgeries aim to bypass the drainage system that’s clogged in the eye or to remove the top layer of the drain to release pressure on the optic nerve, said Dr. Anupama Anchala, ophthalmologist and glaucoma specialist at Northwestern Memorial Hospital.
And the Glaucoma Research Foundation just launched an initiative to fund research, especially using stem cells, aimed at replacing or regenerating damaged optic nerves – in effect, reversing glaucoma no matter when it’s discovered.
“We see ourselves as a venture capitalist, looking to fund the best and brightest investigators and newest ideas with a $5 million annual budget,” said Thomas M. Brunner, president and CEO of the San Francisco-based foundation.
One researcher receiving foundation funding says he believes scientists and clinicians can figure out how to repair the optic nerve before it is lost and/or regenerate the optic nerve in patients who are already blind.
Research is under way to program stem cells that doctors would insert in the back of the eye to replace lost optic-nerve fibers; other research is looking at hijacking some of the circuitry in the retina and optic nerve to protect the nerve, said David Calkins, professor of ophthalmology and visual sciences and director of the Vanderbilt Vision Research Center at Vanderbilt University in Nashville, Tenn.
“Both goals, with sufficient funding and energy, are achievable in the next decade,” he said. “We’re talking about curing blindness.”