Dietary supplements slow down advanced dry macular degeneration

In a new data analysis, researchers at the National Institutes of Health (NIH) found that taking a daily supplement containing antioxidant vitamins and minerals slowed the progression of advanced dry age-related macular degeneration (AMD), potentially helping people with the disease preserve their central vision. The researchers looked at original retinal scans of participants in the Age-Related Eye Disease Studies (AREDS and AREDS2) and found that for people with advanced dry AMD, taking the antioxidant supplement slowed the expansion of geographic atrophy regions toward the central foveal region of the retina. The study was published in the journal Ophthalmology.

“We have long known that AREDS2 supplements help slow progression from intermediate to late AMD. Our analysis shows that taking AREDS2 supplements may also slow disease progression in people with late dry AMD,” said Tiarnan Keenan, MD, PhD, of the NIH’s National Eye Institute (NEI) and lead author of the study. “These findings support the continued use of AREDS2 supplements by people with late dry AMD.”

In their new analysis, the researchers looked at the original retinal scans of participants in the AREDS (318 participants total, 392 eyes) and AREDS2 (891 participants total, 1,210 eyes) trials who developed dry AMD, calculating the position and rate of expansion of their geographic atrophy regions. For people who developed geographic atrophy in their central vision, the supplements had little benefit. But for the majority of those who developed geographic atrophy away from the fovea, the supplements slowed the rate of expansion toward the fovea by about 55% over an average of three years.

In early and intermediate forms of AMD, the light-sensitive retina at the back of the eye develops small yellow deposits of fatty proteins called drusen. As the disease progresses to the advanced stages, patients may develop leaky blood vessels (wet AMD) or lose areas of light-sensitive cells in the retina (dry AMD). Geographic atrophy of these areas slowly expands over time, leading to progressive loss of central vision.

THE original AREDS test found that a supplement formula containing antioxidants (vitamin C, E, and beta-carotene), along with zinc and copper, could slow the progression of mid- to late-stage AMD. AREDS2 subsequent test The researchers found that replacing beta-carotene with antioxidants like lutein and zeaxanthin improved the effectiveness of the supplement formula and eliminated some risks. At the time, neither trial found additional benefits once participants developed advanced disease.

However, this original analysis did not account for a phenomenon called “foveal preservation” in late-onset dry AMD. Although all areas of the retina are sensitive to light, the area that gives us the greatest central visual acuity is called the fovea. Many people with dry AMD first develop geographic atrophy outside of this foveal region, and they only lose central vision as the areas of geographic atrophy extend into the foveal area.

“Our high-acuity central vision is essential for tasks like reading and driving. Given that there are few treatment options for people with advanced dry AMD to maintain or restore their vision, antioxidant supplementation is a simple measure that can slow central vision loss, even for people with advanced disease,” Keenan said. “We plan to confirm these results in a dedicated clinical trial in the near future.”

Learn more about AREDS and AREDS2

The study authors are Keenan, Elvira Agrón, and Emily Chew, MD, of NEI, Pearse Keane, MD, of Moorfields Eye Hospital, United Kingdom, and Amitha Domalpally, MD, PhD, of the University of Wisconsin-Madison. The research was funded by the NEI Intramural Research Program. Funding for the AREDS and AREDS2 studies, under contracts NOI-EY-0-2127, HHS-N-260-2005-00007-C, and N01-EY-5-0007, was provided by NEI and the NIH Office of Dietary Supplements, the National Center for Complementary and Alternative Medicine, the National Institute on Aging, the National Heart, Lung, and Blood Institute, and the National Institute of Neurological Disorders and Stroke. The AREDS and AREDS2 studies, clinicaltrials.gov numbers NCT00000145 and NCT00345176, respectively, were conducted at the NIH Clinical Center.

Reference: Keenan TDL, Agrón E, Keane PA, Domalpally A, and Chew EY, for the AREDS and AREDS2 research groups. “Oral antioxidant and lutein/zeaxanthin supplements slow the progression of geographic atrophy toward the fovea in age-related macular degeneration.” Ophthalmology. Epub 2024 Jul 16. doi: 10.1016/j.ophtha.2024.07.014