As many as 15 million people in the United States have some form of age-related macular degeneration, a leading cause of vision loss among people 50 and older.
Nine out of 10 of them have the dry form, which affects vision but does so more slowly and usually less dramatically than the wet form. Macular degeneration usually starts as dry AMD, but 10% to 15% moves into wet.
With wet macular degeneration, a major concern is bleeding in the eye that can destroy central vision.
In dry macular degeneration, the concern is when deposits called drusen start getting out of control.
Drusen are small, yellowish deposits that form under the retina of the eye. They’re like little pebbles, made of proteins and lipids.
The good aspect of dry macular degeneration is that it’s much less likely than wet to impair the vision and can take decades before it does, said Dr. Richard Hamilton, a vitreoretinal ophthalmologist with Retina Partners of Florida in Lakeland and Winter Haven.
If those little pebble-like deposits get bigger and more widespread, however, they can cause cells in the macula to disappear.
The macula is the center part of the retina.
Losing those cells can leave blind spots and, if the loss is very widespread, a big blind spot, Hamilton said.
If it spreads far enough, the condition or complication is called geographic atrophy, atrophy being a medical word for cell loss.
Symptoms of dry ARMD (age-related macular degeneration) include needing more light while reading, trouble recognizing faces, blurriness of printed words and trouble adjusting to dim light.
Treatment focuses on prevention, not cure
With dry macular degeneration, the focus has been prevention more than cure: approaches such as eating healthy, not smoking and taking a specific high-dose combination of vitamins and minerals.
That combination as recommended is AREDS2. AREDS2 came after the first AREDS and substituted the antioxidants lutein and zeaxanthin for beta-carotene.
AREDS is an acronym for Age-Related Eye Disease Studies. Vitamins C, E and zinc were in both AREDS1 and AREDS2.
The AREDS studies found taking AREDS supplements reduced risk of progression from intermediate to advanced AMD by about 25 percent, according to the National Institutes of Health, which funded the studies.
A 10-year analysis of AREDS2 data showed it was more effective than the original AREDS at reducing the risk of progression of age-related macular degeneration. It also reduced risk of lung cancer due to beta-carotene, NIH said.
In AREDS2, beta-carotene was removed because it had caused lung cancer in 1% of patients in the study who were smokers, Hamilton said.
“Lutein is not the player people think it is,” he cautioned during a Nov. 5 Matters of Vision program in Lakeland.
“It’s really about the zinc and vitamin C. Those are the big movers,” he said, adding, “People who had poor diets (in the study) were helped by lutein more than others.”
AREDS found benefit in slowing progression in patients who had moderate to severe macular degeneration and met other criteria, said Dr. Scott Friedman, a vitreoretinal ophthalmologist at Florida Retina Consultants in Lakeland and Winter Haven.
It didn’t find benefits for patients with early macular degeneration, but that doesn’t rule out benefits decades down the road, he said, adding that he tells patients who have mild AMD or a family history of it “There’s probably not a lot of detriment” in taking the combination.
The American Academy of Ophthalmology, www.aao.org, recommends people with no eye problems or no risk factors get a baseline eye exam at age 40. Early signs of disease and changes in vision often start then. People of any age who have symptoms or risk factors for eye disease shouldn’t wait until age 40, it adds. Risk factors include diabetes, high blood pressure or a family history of eye disease.
No injections yet for dry variety
Unlike patients with wet macular degeneration, those with dry macular degeneration aren’t advised to get injections of drugs to treat it.
At least, not yet.
That could change for some people whose drusen deposits have spread far enough to create a sufficiently large area of blind spots for concern, Friedman said. That’s the condition referred to above as geographic atrophy.
Apellis Pharmaceuticals is awaiting a decision from the Food and Drug Administration on its new drug application for pegcetacopian, a treatment targeting “excessive activation” of a part of the body’s immune system called the “complementary cascade.”
About 1 million people in the United States have geographic atrophy, the company said. It reported that three studies of its drug treatment found it “meaningfully slowed” geographic atrophy progression.
“The retina community is anxiously awaiting an FDA decision on Apellis’ new drug for dry ARMD/geographic atrophy targeting the complementary cascade,” Hamilton said.
“If approved, it would represent the first injectable drug for dry ARMD.”
Robin Williams Adams can be reached at email@example.com.
This article originally appeared on The Ledger: Dry macular degeneration develops slower, but can still impair vision