Photobiomodulation: Assessing the Role of Light Therapy in Dry AMD

Dry age-related macular degeneration (AMD) is a progressive disease typically treated in late stage.^1-3 Untreated early/intermediate AMD may progress to geographic atrophy, causing irreversible vision loss and blindness, with significant direct and indirect medical costs.^*4-7 However, until recently, treatment options for early/intermediate dry AMD have remained limited.

Photobiomodulation (PBM), or the medical application of light in the 500 to 1000 nm range to stimulate cellular function,^8,9 may fill this treatment gap. In particular, Valeda^TM PBM (Alcon) uses strategically selected wavelengths of light to target key cellular mechanisms relevant to AMD pathology.^8,9

At a recent symposium, four international retina experts gathered to review data from the LIGHTSITE III study, which was the largest and longest trial of PBM to date, and the LIGHTSITE IIIb extension study. Below is a summary of the proceedings, reviewing the functional and anatomical outcomes from the study, as well as the mechanism of action associated with Valeda^TM PBM treatment.

1. Jaffe GJ, Boyer D, Hu A, et al. Long-term efficacy and safety of photobiomodulation in dry age-related macular degeneration (LIGHTSITE III: 24-month analysis). Retina. Accepted Manuscript. Published online March 3, 2026.

2. Fernandes AR, Zielińska A, Sanchez-Lopez E, et al. Exudative versus nonexudative age-related macular degeneration: physiopathology and treatment options. Int J Mol Sci. 2022;23(5):2592.

3. Evans J. Antioxidant supplements to prevent or slow down the progression of AMD: a systematic review and meta-analysis. Eye (Lond). 2008;22(6):751-760.

4. Cost-effectiveness analysis of photobiomodulation therapy with the Valeda Light Delivery System for treatment of dry AMD in the English healthcare setting. In submission.

5. Nissen AHK, Torp TL, Vergmann AS. Clinical outcomes of treatment of geographic atrophy: a narrative review. Ophthalmol Ther. 2025;14(6):1173-1181.

6. Rajanala K, Dotiwala F, Upadhyay A. Geographic atrophy: pathophysiology and current therapeutic strategies. Front Ophthalmol (Lausanne). 2023;3:1327883.

7. Rein DB, Wittenborn JS, Zhang P, et al. The economic burden of vision loss and blindness in the United States. Ophthalmology. 2022;129(4):369-378.

8. Ball KA, Castello PR, Poyton RO. Low intensity light stimulates nitrite-dependent nitric oxide synthesis but not oxygen consumption by cytochrome c oxidase: Implications for phototherapy. J Photochem Photobiol B. 2011;102(3):182-191.

9. Wong-Riley MT, Liang HL, Eells JT, et al. Photobiomodulation directly benefits primary neurons functionally inactivated by toxins: role of cytochrome c oxidase. J Biol Chem. 2005;280(6):4761-4771.

*Patients with geographic atrophy often experience a gradual and painless loss of central vision, resulting in difficulty reading, recognizing faces, or performing activities that require detailed vision. Vision loss (VL) and blindness, especially in older populations result in substantial economic impacts from increased medical costs, and higher risk of nursing home (NH) placement. According to a recent (2017 dollars) estimate, the burden of VL in the US totaled $134.2 billion: $98.7 billion in direct costs and $35.5 billion in indirect costs. The largest burden components were NH ($41.8 billion), other medical care services ($30.9 billion), and reduced labor force participation ($16.2 billion), Those with VL incurred $16,838 per year in incremental burden.