Photobiomodulation for Macular Degeneration: What the Evidence Shows

For decades, people diagnosed with dry AMD heard some version of the same message: take your AREDS2 vitamins, check your Amsler grid, and come back in six months. Unlike wet AMD, which has had effective injections since the mid-2000s, early and intermediate dry AMD had no treatment aimed at the disease itself.

That changed in November 2024, when the U.S. Food and Drug Administration authorized a light-based therapy called photobiomodulation for dry AMD. This article explains what PBM is, how it is thought to work in the retina, what the clinical trials actually showed, who may be a candidate, and the questions that remain open. If you are new to the two forms of AMD, start with dry vs. wet AMD.

What is photobiomodulation?

Photobiomodulation uses specific wavelengths of low-energy light to change how cells behave. It is not a laser that burns or seals tissue, and it is not the same as the "red light" gadgets sold online. The light levels are low enough that they produce no heat damage, and the goal is to nudge cell metabolism rather than destroy anything.

The Valeda system delivers three wavelengths: 590 nm (yellow), 660 nm (red), and 850 nm (near-infrared). The patient sits at the device with the eyes closed while light pulses through the eyelids for a few minutes per eye.

Why light might help a tired retina

The macula is among the most metabolically demanding tissues in the body. Photoreceptors and the retinal pigment epithelium (RPE) beneath them burn enormous amounts of energy, and that energy comes from mitochondria. In AMD, mitochondria in the RPE become damaged and less efficient, oxidative stress builds, and waste deposits called drusen accumulate.

The leading explanation for PBM centers on an enzyme inside mitochondria called cytochrome c oxidase. This enzyme absorbs red and near-infrared light. When it does, laboratory studies suggest it:

• Increases production of ATP, the cell's energy currency
• Releases nitric oxide that can otherwise slow mitochondrial respiration
• Shifts signaling pathways toward lower inflammation and less oxidative stress

The theory is that a short dose of light helps struggling RPE and photoreceptor cells work better and survive longer. The yellow wavelength is thought to act through different pathways, including effects on inflammation. These mechanisms are well supported in cell and animal studies, but how much each contributes in human eyes is still being worked out.

What the clinical trials showed

The evidence for PBM in dry AMD comes mainly from the LIGHTSITE series of randomized, sham-controlled trials sponsored by LumiThera, the device's maker. In a sham-controlled trial, the comparison group goes through an identical-looking procedure without the active light, so neither patients nor examiners know who got the real treatment.

Two results stand out. First, the vision gain: about one line on the eye chart, sustained over roughly two years with repeat treatments. The trial also recorded improvements in vision-related quality of life.

Second, and potentially more important, is the lower rate of progression to geographic atrophy (GA), the advanced form of dry AMD in which retinal cells die and leave permanent blind spots. If that finding holds up, PBM would be the first treatment shown to help keep intermediate dry AMD from advancing. The investigators noted that GA progression was not a prespecified primary endpoint, so it needs confirmation in future studies.

On the strength of LIGHTSITE III, the FDA granted the Valeda system De Novo marketing authorization in November 2024 for the treatment of patients with dry AMD. De Novo is the pathway for a new kind of low-to-moderate risk device that has no existing equivalent on the market.

Who may be a candidate

LIGHTSITE III enrolled people with early to intermediate dry AMD, typically with best-corrected vision between 20/32 and 20/100. That profile describes the patients most likely to benefit:

• Likely candidates: intermediate dry AMD with drusen and some vision loss, but no wet AMD and no large areas of atrophy in the center of the macula
• Less likely to benefit: advanced geographic atrophy that already involves the center of vision, where the cells PBM aims to support are largely gone
• Not a substitute: for anyone with wet AMD, which still needs anti-VEGF injections to control leaking blood vessels

LIGHTSITE I also found that patients with earlier-stage disease responded more strongly. A retina specialist confirms the stage with a dilated exam and an OCT scan before recommending treatment.

What treatment involves

In the trials, one treatment series was 9 sessions given three times a week over 3 to 5 weeks. Series were repeated every 4 months. Each session takes only a few minutes, requires no injections or eye drops, and is painless. Most people return to normal activities right away.

The repeat schedule matters. LIGHTSITE I showed that vision gains faded between series, which suggests PBM works more like ongoing maintenance than a one-time fix. That means a real time commitment: around 27 office visits a year on the trial schedule.

Limitations and open questions

PBM is promising, but a balanced view includes its limits:

• Modest effect size. The average gain is about one line on the chart. Some patients notice a clear difference; others notice little.
• Small, sponsor-funded trials. LIGHTSITE III randomized 100 patients, and the trials were funded by the manufacturer. Independent replication would strengthen confidence, especially in the geographic atrophy findings.
• Mixed earlier data. A European trial, LIGHTSITE II, produced less consistent results, which drew debate in the literature.
• Cost and access. Insurance coverage varies, and many patients pay out of pocket. A 2026 cost-effectiveness analysis found PBM cost-effective at common U.S. thresholds, but its authors also called for independent confirmation of the atrophy benefit.
• Long-term durability. Data beyond two years are still limited.

None of this makes PBM a poor option. It makes it a reasonable one to discuss with a retina specialist who knows the patient's eyes.

PBM works alongside the basics, not instead of them

Photobiomodulation is an addition to proven AMD care, not a replacement for it. The foundations still apply to everyone with intermediate dry AMD:

1. AREDS2 nutrition. The AREDS2 formula (vitamins C and E, zinc, copper, lutein, and zeaxanthin) lowered the risk of progressing to advanced AMD by about 25% in people with intermediate disease. See AREDS and AREDS2 Explained.
2. Not smoking. Smoking is the largest modifiable risk factor for AMD progression.
3. A Mediterranean-style diet. Leafy greens, colorful vegetables, and fish are linked to lower progression risk.
4. Home monitoring. Daily Amsler grid checks help catch the sudden distortion that can signal conversion to wet AMD, which needs prompt treatment.
5. Regular retina exams. OCT imaging tracks drusen and atrophy over time and shows whether a treatment is helping.

The mitochondrial story behind PBM also highlights a broader theme in AMD research: the macula's energy demand and oxidative load are central to the disease. That is why nutrition that supports the retina's antioxidant defenses remains a core part of long-term macular health.

The bottom line

Photobiomodulation is the first FDA-authorized treatment for early and intermediate dry AMD. In randomized trials it improved vision by about one line and may slow progression to geographic atrophy, with a favorable safety record. It requires repeat sessions several times a year, the effect is modest, and larger independent studies are still needed.

For people with intermediate dry AMD, it is worth asking a retina specialist whether PBM fits their stage of disease, their schedule, and their budget, while continuing the nutrition, monitoring, and lifestyle steps that remain the backbone of care.

If you are comparing eye vitamin formulas, our science page lists the doses used in the AREDS2 trial.

Related reading

• Dry vs. Wet Macular Degeneration: What's Actually Happening in Your Eye
• AREDS and AREDS2 Explained: How the Eye Vitamin Trials Worked
• Nutrition and Eye Health: What the Research Actually Shows

References

1. Markowitz SN, et al. A double-masked, randomized, sham-controlled, single-center study with photobiomodulation for the treatment of dry age-related macular degeneration (LIGHTSITE I). Retina. 2020;40(8):1471-1482. doi:10.1097/IAE.0000000000002632
2. Boyer D, et al. LIGHTSITE III: 13-month efficacy and safety evaluation of multiwavelength photobiomodulation in nonexudative (dry) AMD. Retina. 2024;44(3):487-497. doi:10.1097/IAE.0000000000003980
3. Jaffe GJ, et al. Long-term efficacy and safety of photobiomodulation in dry AMD (LIGHTSITE III: 24-month analysis). Retina. 2026;46(5):783-795. doi:10.1097/IAE.0000000000004822
4. Burton B, et al. A response to: letter to the editor regarding "LIGHTSITE II randomized multicenter trial." Ophthalmol Ther. 2024;13(4):1055-1060. doi:10.1007/s40123-024-00896-0
5. Watane A, et al. Cost-effectiveness of photobiomodulation for intermediate dry AMD: a model-based analysis using the LIGHTSITE III 24-month trial. Am J Ophthalmol. 2026;291:324-333. doi:10.1016/j.ajo.2026.07.035
6. LumiThera. LumiThera obtains FDA authorization of Valeda treatment for dry AMD patients to improve vision. Business Wire, November 4, 2024. businesswire.com

This article is for general education and is not medical advice. Talk with your eye doctor before starting any treatment or supplement, especially if you smoke, take other medicines, or have a health condition. These statements have not been evaluated by the Food and Drug Administration. TruVista products are not intended to diagnose, treat, cure, or prevent any disease.