A major study has found AREDS and AREDS2 oral supplements slowed geographic atrophy (GA) progression towards the central macula,1 a finding that would be “highly valuable”, potentially helping people with late-stage disease preserve their central vision.
“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 lead author Dr Tiarnan Keenan, from the National Eye Institute in the United States.2 “These findings support the continued use of AREDS2 supplements by people with late dry AMD.”
Researchers re-analysed data from the Age-Related Eye Diseases Studies (AREDS and AREDS2) and found that for people with late-stage dry AMD, taking a daily antioxidant supplement slowed expansion of GA regions towards the central foveal region of the retina.
This was likely due to the supplements augmenting the natural phenomenon of foveal sparing.
For those people who developed GA in their central vision, the supplements had little benefit, the study found.
However, in most cases, GA arises away from the central macula, expanding gradually in all directions. When it involves “the macular centre-point and has sufficient size, it is usually accompanied by severely decreased visual acuity… thus, the time taken for noncentral GA to reach the macular centre-point is an important metric”, the authors said.
The AREDS2 supplements slowed the rate of expansion towards the fovea by approximately 55% over an average of three years.
These findings have important implications for the potential preservation of visual function in the long term
AREDS Supplements
AREDS supplements refer to a range of supplements with formulas based on the Age-Related Eye Disease Studies. AREDS2 is a modified formula that replaced beta-carotene with lutein/zeaxanthin.
“The results of our analyses suggest that vitamin C, vitamin E, and lutein/zeaxanthin may make important contributions to the known phenomenon of foveal sparing from GA in AMD and that oral supplementation may augment this natural phenomenon,” the study authors wrote.
Supplements are currently recommended for people with intermediate stage AMD in one or both eyes, to help lower the risk of progression to late AMD, or for those with late-stage AMD in one eye only, to help lower the risk of developing it in the other eye.3
Neither AREDS trial initially detected any further benefit once participants had developed late-stage disease. However, the authors of the new analysis said the original studies did not account for a phenomenon in the dry form of late AMD called “foveal sparing”.
This latest study suggests patients with non-central GA in one or both eyes may benefit most from vitamins C and E, and lutein/zeaxanthin, and that the addition of zinc could also decrease the risk of neovascular AMD. Additionally, the study found a preference for the low zinc 25 mg AREDS2 formula in relation to visual acuity, reporting that “a significant difference was observed for low versus high zinc… with slower visual acuity decline in participants randomised to low zinc”.
The findings indicate that the same AREDS2 formulation currently recommended for intermediate AMD would simplify treatment for individuals, as they could continue taking the same AREDS2 supplement both before and after progression from intermediate AMD to GA.
Important Implications
GA, the defining lesion of the atrophic subtype of late AMD, is estimated to affect more than five million people worldwide. No treatment is available to prevent its occurrence or restore vision. In the United States, two drugs have received Food and Drug Administration approval: pegcetacoplan (a C3 complement inhibitor) and avacincaptad pegol (a C5 complement inhibitor).
“However, limitations of both drugs include administration by repeated intravitreal injection… relatively modest efficiency, important side effects… and high cost,” the study authors noted.
“Therefore, additional therapeutic approaches to slow GA progression, ideally with oral administration, favourable safety record, and modest cost, remain a high priority.”
“Our findings may justify a prospective randomised controlled trial of oral antioxidant and lutein/zeaxanthin supplementation in eyes of individuals with noncentral GA. If the results were confirmed, this would suggest a new standard of care for patients with GA.”
References
- Keenan TDL, Agrón E, Chew EY, et al.; Age-related eye disease study research group; Age-related eye disease study 2 research group. Oral antioxidant and lutein/zeaxanthin supplements slow geographic atrophy progression to the fovea in age-related macular degeneration. Ophthalmology. 2024 Jul 16:S0161-6420(24)00425-1. doi: 10.1016/j.ophtha.2024.07.014. Epub ahead of print.
- National Institutes of Health, Supplements slow disease progression during late stage of “dry” age-related macular degeneration (media release, 16 Jul 2024), available at nih.gov/news-events/news-releases/supplements-slow-disease-progression-during-late-stage-dry-age-related-macular-degeneration [accessed Dec 2024].
- Macular Disease Foundation Australia, Supplements for AMD (webpage), available at: mdfoundation.com.au/about-macular-disease/age-related-macular-degeneration/supplements-for-amd/ [accessed Nov 2024].
