New research out of the National Institutes of Health (NIH)’s National Eye Institute (NEI)—published in Ophthalmology—have identified significant benefits associated with taking a daily supplement to potentially slow the progression of geographic atrophy (GA) in age-related macular degeneration (AMD).
Where to begin?
We’ll start with the basis of this study, which included researchers reviewing the original retinal scans of participants from both the NEI-sponsored Age-Related Eye Disease Studies:
- AREDS
- AREDS2
Give me an AREDS and AREDS2 refresh.
These studies were designed to evaluate the clinical course, prognosis, and risk factors associated with AMD and cataract.
The following nutrients’ (vs placebo’s) effect on the progression of AMD, cataract, and other related vision loss were assessed:
- High-dose antioxidants (Vitamins C & E; beta carotene) (AREDS)
- Zinc + copper (AREDS)
- Lutein + zeaxanthin (AREDS2)
- Omega-3 fatty acids (AREDS2)
What were the findings from both studies?
First: Both AREDS and AREDS2 evaluated patients diagnosed with AMD and cataract.
- AREDS results
- After 5 years, patients at a high risk for developing advanced AMD reduced their risk by an estimated 25% when treated with a combination of antioxidants and zinc + copper (the final AREDS formula).
- Note: This formula also reduced the risk of central vision loss by 19% in this group. Notably, it did not decrease the risk for cataract
- 5-year follow-up
- After 10 years post-initial enrollment, 70% of participants were reported to be taking the AREDS formula
- Further, those who had been assigned to the zinc + copper formula were 25-30% less likely to develop advanced AMD (vs placebo patients)
- After 5 years, patients at a high risk for developing advanced AMD reduced their risk by an estimated 25% when treated with a combination of antioxidants and zinc + copper (the final AREDS formula).
- AREDS2 results
- Adding in omega-3 fatty acids or lutein + zeaxanthin to the AREDS formula had no added overall effect on advanced AMD risk
- Conversely: Taking antioxidants without beta-carotene but with lutein + zeaxanthin demonstrated an incremental benefit (vs the AREDS formula alone)
- Adding in omega-3 fatty acids or lutein + zeaxanthin to the AREDS formula had no added overall effect on advanced AMD risk
Alrighty, I’m up to date. Talk about this new research.
The overarching purpose behind this study was to determine whether the use of oral supplements may, in fact, slow GA progression in AMD—potentially serving as an alternative to the current standard of care with frequent intravitreal injections.
And how was this done?
Investigators performed a post-hoc analysis of the original retinal scans from the AREDS/AREDS2 data of the following GA participants:
- AREDS: 318 patients (392 eyes)
- AREDS2: 891 patients (1,210 eyes)
Then: These scans were used to measure the following:
- Changes in GA proximity to the central macula (or fovea)
- Total GA growth over time
So what did they find?
Patients who developed GA in the central foveal region saw little to no benefits from the supplements. Interestingly, patients with GA developed far from the fovea (non-central or non-foveal GA) had their rate of GA expansion toward the fovea slow—by an estimated 55% over a 3-year period.
Zero in on these non-central GA patients.
In the AREDS study (n = 208 eyes), the proximity-based GA progression towards the central macula was found to be “significantly slower with randomization to antioxidants” compared to no antioxidants, respectively:
- 50 μm/year (95% Confidence interval [CI] 38.0-63.4 μm/year) vs
- 72.9 μm/year (95% CI 61.3-84.5 μm/year; p=0.012)
And in the AREDS2 study, patients receiving antioxidants without beta-carotene (n = 325 eyes) had their proximity-based GA progression be “significantly slower with randomization to lutein-zeaxanthin” compared to none, respectively:
- 80.1 μm/year (95% CI 60.9-99.3 μm/year) vs
- 114.4 μm/year (95% CI 96.2-132.7 μm/year; p=0.011)
What did the investigators have to say about this?
According to lead study author Tiarnán Keenan, MD, PhD, of the NEI, the researchers had already known that AREDS2 supplements help to slow intermediate to late AMD progression.
However, this latest analysis supports the findings that continued use of “taking AREDS2 supplements can also slow disease progression in people with late dry AMD,” stated Dr. Keenan.
And the reason for this?
Per the investigators, this was likely due to the fact that the simple step of taking antioxidants or lutein/zeaxanthin supplements “likely augmented the natural phenomenon of foveal sparing.”
So what’s next in this research?
The authors stated that they intend to confirm these findings in a future clinical trial… so we’ll just have to stay tuned.