In a new analysis, researchers at the National Institutes of Health (NIH) found that taking a daily supplement containing lutein, zeaxanthin, vitamins C and E, zinc, and copper (the formula used in the AREDS2 study) was beneficial in late-stage dry age-related macular degeneration (AMD).

The researchers reviewed the original retinal scans of participants of  the Age-Related Eye Disease Studies (AREDS and AREDS2), who had AMD at baseline, and found that the supplement slowed expansion of geographic atrophy regions toward the central foveal region of the retina.

“We’ve known for a long time that AREDS2 supplements help slow the progression from intermediate to late AMD. Our analysis shows that taking AREDS2 supplements can also slow disease progression in people with late dry AMD,” said Tiarnan Keenan, MD, PhD, of 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.”

The researchers reviewed retinal scans from AREDS (318 participants, 392 eyes) and AREDS2 (891 participants, 1210 eyes) who developed dry AMD, calculation the position and expansion rate of their regions of geographic atrophy.

For those who developed geographic atrophy in their central vision, the supplements had little benefit. But for the majority who developed geographic atrophy in the fovea, the supplements slowed the rate of expansion toward the fovea by approximately 55% over an average of three years, the authors concluded.

In early and intermediate AMD, the light-sensing retina at the back of the eye develops small yellow deposits of fatty proteins called drusen. When the disease progresses to late stage, people can either develop “wet” AMD, in which they develop leaky blood vessels, or “dry” AMD, in which they lose regions of light-sensitive cells in the retina. Geographic atrophy slowly expands over time, causing people to progressively lose their central vision.

The original AREDS trial found that a supplement formula containing antioxidants (vitamins C, E, and beta-carotene) along with zinc and copper reduced progression from intermediate to late-stage AMD. AREDS2 swapped the beta-carotene with lutein and zeaxanthin, which improved the efficacy of the supplement and eliminated certain risks.

At the time, neither trial detected benefits once patients developed late-stage disease.

However, that original analysis didn’t account for a phenomenon in the dry form of AMD called “foveal sparing.” While all regions of the retina are sensitive to light, the region that gives the highest-acuity central vision is the fovea. Many people with dry AMD develop geographic atrophy outside of this foveal region, and only lose their central vision when the geographic atrophy regions expand into the central fovea.

“Our high acuity central vision is essential for tasks like reading and driving. Given that there are few therapeutic options for people with late-stage dry AMD to retain or restore their vision, antioxidant supplementation is a simple step that may slow central vision loss, even for those with late disease,” Keenan said. “We plan to confirm these findings in a dedicated clinical trial in the near future.”