Age-related macular degeneration (AMD) remains a leading cause of irreversible vision loss and is now understood as a multifactorial disease characterized by oxidative stress, mitochondrial dysfunction, chronic inflammation, and vascular compromise.
The Age Related Eye Disease Studies (AREDS and AREDS2) established the standard of care for intermediate AMD, demonstrating an approximately 25% reduction in progression to advanced disease with targeted antioxidant and mineral supplementation.1,2
Increasingly, AMD is recognized as involving cellular energy failure and metabolic stress, with elevated homocysteine emerging as a potentially modifiable risk marker. Together, mitochondrial dysfunction and homocysteine-mediated vascular injury may act upstream of several downstream features of disease, offering an opportunity to expand beyond traditional antioxidant-based strategies.
AREDS/AREDS2: The foundation
AREDS demonstrated that vitamins C and E, beta-carotene, and zinc reduce progression to advanced AMD.1 AREDS2 improved safety by replacing beta-carotene with lutein and zeaxanthin while maintaining efficacy.2
These trials validated nutrition as disease-modifying therapy—but did not address upstream metabolic contributors such as mitochondrial dysfunction or homocysteine dysregulation.
Mitochondrial dysfunction: An early driver
The retina—particularly the retinal pigment epithelium (RPE)—has among the highest metabolic demands in the body.3,4 In AMD, mitochondrial abnormalities include reduced oxidative phosphorylation, increased reactive oxygen species (ROS), mitochondrial DNA damage, and impaired mitophagy.4,5
This results in bioenergetic insufficiency, contributing to RPE dysfunction and photoreceptor loss. Notably, mitochondrial dysfunction is increasingly considered an early initiating event in AMD.5
Elevated homocysteine: A modifiable risk factor
Homocysteine is a central intermediate in one-carbon metabolism. When elevated, it contributes to:
- Endothelial dysfunction
- Reduced nitric oxide bioavailability
- Microvascular dysfunction, including in the retinal and choroidal circulation
- Oxidative stress and inflammation
Elevated homocysteine has been associated with increased AMD risk and progression.7 Importantly, it is modifiable through targeted nutritional intervention, making it clinically actionable.
Download the flowchart here!
Cycle of Mitochondrial Dysfunction in AMD Flowchart
Use this cheat sheet to review and educate patients on the role of mitochondrial dysfunction and elevated homocysteine in AMD progression.
B vitamins: Linking vascular and mitochondrial health
B vitamins (B6, B9, B12) are essential cofactors in homocysteine metabolism and mitochondrial function.8 For example, folate and B12 support remethylation of homocysteine, while B6 supports transsulfuration and glutathione production
When deficient, homocysteine accumulates—driving both vascular injury and mitochondrial dysfunction.6 Thus, B vitamins act upstream, supporting retinal perfusion (vascular integrity) and cellular energy production (mitochondrial function).
Clinical evidence
The Women’s Antioxidant and Folic Acid Cardiovascular Study (WAFACS) demonstrated a 34 to 41% reduction in AMD risk with folic acid, B6, and B12 supplementation over 7.3 years.9
This effect likely reflects homocysteine reduction and improved metabolic resilience, rather than antioxidant activity alone.
Implementation of B vitamins
B vitamins may be considered as an adjunct to AREDS2 in select patients, particularly those with intermediate AMD, elevated homocysteine, cardiovascular co-morbidities, and suboptimal dietary intake or risk of micronutrient insufficiency.
Clinical considerations:
- Assess homocysteine, with consideration of methylmalonic acid (MMA) to evaluate functional B12 status
- Recognize that serum B12 levels may not fully reflect intracellular sufficiency
- Consider bioactive B-vitamin forms (e.g., methylated or reduced folate forms) in patients with impaired metabolism
- Monitor for medication-related depletion (e.g., metformin-associated B12 deficiency)
- B vitamins may be protective earlier in the disease process before structural damage ensues
Check out the Cycle of Mitochondrial Dysfunction in AMD Flowchart!
Looking ahead: The introduction of PreserVision AREDS3
In 2026, Bausch + Lomb introduced PreserVision AREDS3, a next-generation formulation that builds upon the clinically proven AREDS2 nutrient profile by incorporating a unique B-vitamin complex designed to support cellular metabolism, healthy homocysteine levels, and the body’s natural response to oxidative stress.10
Unlike traditional AREDS2 formulations, PreserVision AREDS3 specifically targets several emerging mechanisms implicated in AMD pathophysiology—including mitochondrial dysfunction, vascular compromise, and metabolic stress.
The formulation retains the NEI-recommended AREDS2 nutrients shown to reduce progression risk in moderate-to-advanced AMD, while adding vitamins B1, B2, B3, B5, B6, B7, B9, and B12 based on growing evidence linking B-vitamin status and homocysteine regulation to AMD risk and progression.10
Importantly, the launch of PreserVision AREDS3 reflects a broader shift in AMD management toward earlier, upstream metabolic support rather than focusing exclusively on downstream oxidative damage.
Supporting this approach are epidemiologic findings, mechanistic studies, and randomized clinical trial data—including the Women’s Antioxidant and Folic Acid Cardiovascular Study (WAFACS), which demonstrated a 34% reduction in AMD risk and a 41% reduction in visually significant AMD with supplementation using vitamins B6, B9, and B12.9
Taking a proactive approach to AMD care
As clinicians, recognizing mitochondrial dysfunction and homocysteine as upstream drivers shifts AMD care from reactive to preventative and metabolic. As supporting cellular energy and vascular health earlier may delay progression, it is imperative to educate patients on their role in their ocular health.
To introduce this concept to patients, keep it simple and make reasonable recommendations. The explanation can be as simple as, “Your retina has high energy demands. We need to support the systems that power it and maintain healthy blood flow.” Alongside targeted supplementation, encourage a diet, such as the Mediterranean plan, that is full of leafy greens, fresh vegetables, and fatty fish.
Key takeaways
- AREDS2 remains foundational for intermediate AMD.1,2
- Mitochondrial dysfunction is an early driver of AMD.3,5
- Elevated homocysteine is a modifiable risk factor.7
- B vitamins regulate homocysteine and support mitochondrial health.8
- WAFACS showed a 34 to 41% AMD risk reduction with B vitamins.9
- B vitamins provide vascular and neuroprotective benefits.
- Adjunctive use alongside AREDS2 is clinically reasonable.
- Upstream metabolic care represents the future of AMD management.
