A recent analysis of data reveals that a daily supplement containing antioxidant vitamins and minerals can effectively slow down the advancement of late-stage dry age-related macular degeneration (AMD), potentially aiding individuals with late-stage AMD in preserving their central vision. Researchers at the National Institutes of Health (NIH) conducted this study by examining retinal scans of participants in the Age-Related Eye Diseases Studies (AREDS and AREDS2), finding that the antioxidant supplement notably decelerated the expansion of geographic atrophy regions towards the central foveal region of the retina. The research outcomes were published in the Ophthalmology journal.
“The AREDS2 supplements have been known to delay the progression from intermediate to late AMD for quite some time. Our analysis now demonstrates their capability to slow down the disease advancement in individuals with late dry AMD,” stated Tiarnan Keenan, M.D., Ph.D., from NIH’s National Eye Institute (NEI) and the lead researcher of this study. “These findings advocate for the continued usage of AREDS2 supplements among individuals with late dry AMD.”
The researchers reviewed the original retinal scans from participants in the AREDS (318 participants, 392 eyes) and AREDS2 (891 participants, 1210 eyes) trials who developed dry AMD. By calculating the position and expansion rate of their regions of geographic atrophy, it was found that for those developing geographic atrophy in their central vision, the supplements had minimal benefits. However, for the majority experiencing geographic atrophy distanced from the fovea, the supplements reduced the expansion rate towards the fovea by approximately 55% over an average of three years.
Age-related macular degeneration progresses through the development of small yellow deposits of fatty proteins known as drusen in the light-sensing retina at the rear of the eye. In the late stage, individuals may develop abnormal blood vessel growth (“wet” AMD) or encounter loss of light-sensitive cells in the retina (“dry” AMD). The gradual expansion of geographic atrophy regions leads to a progressive loss of central vision.
The original AREDS trial demonstrated that a supplement comprising antioxidants (vitamin C, E, and beta-carotene), in addition to zinc and copper, could hinder the progression from intermediate to late-stage AMD. The subsequent AREDS2 trial revealed that replacing beta-carotene with lutein and zeaxanthin enhanced the supplement’s efficacy and eliminated certain risks. However, neither trial identified any additional benefits once late-stage disease was established.
Nevertheless, the initial analysis failed to consider the “foveal sparing” phenomenon present in the dry form of late AMD. Many individuals initially develop geographic atrophy outside the foveal region, only experiencing central vision loss once the atrophy regions reach the foveal area.
“Our high acuity central vision is crucial for tasks like reading and driving. Considering the limited options available for individuals with late-stage dry AMD to maintain or regain their vision, antioxidant supplementation presents a simple yet effective method to slow down central vision decline, even in late-stage disease scenarios,” Keenan explained. “We intend to validate these findings through a dedicated clinical trial in the near future.”
The study’s authors include Keenan, Elvira Agrón, and Emily Chew, M.D. from NEI, Pearse Keane, M.D. from Moorfields Eye Hospital, U.K., and Amitha Domalpally, M.D., Ph.D., University of Wisconsin-Madison. The research received support from the NEI Intramural Research Program, and funding for the AREDS and AREDS2 studies was provided by NEI, 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 clinical trials for AREDS and AREDS2 were conducted at the NIH Clinical Center with the respective identifiers NCT00000145 and NCT00345176.
