Summary: In non-infected diabetic foot ulcers, 660 nm photobiomodulation reduced ulcer area significantly over 10 weeks but did not outperform a 904 nm infrared laser; energy densities ≥8 J/cm² worked better than 4 J/cm².
PICO Summary
| Element | Detail |
|---|---|
| Population | Patients with non-infected diabetic foot ulcers on standard wound care (double-blind dose-response trial). |
| Intervention | 660 nm HeNe photobiomodulation, twice weekly for 10 weeks, at 4, 8, or 12 J/cm². |
| Comparison | 904 nm GaAs infrared laser at 10 J/cm², twice weekly for 10 weeks. |
| Outcome | All arms achieved significant ulcer-area reduction (p<0.0001) with no between-group difference at 5 or 10 weeks. Best response at ≥8 J/cm²; the 4 J/cm² dose had fewer responders. |
660 nm laser for diabetic foot ulcers
Double-blind RCT · non-infected DFU · 10 weeks
Both red 660 nm and infrared 904 nm laser significantly shrank non-infected diabetic foot ulcers over 10 weeks with no difference between wavelengths; a dose of at least 8 J/cm² gave the best response.
Expert Commentary
Photobiomodulation for diabetic foot ulcers has a plausible mitochondrial mechanism and a large but messy evidence base, so I came to this dose-response trial hoping it would sharpen the picture, and it partly does. The useful, actionable signal is about fluence: doses of 8 J/cm² or more produced more responders than 4, which tells me that if this is offered, sub-threshold energy just wastes everyone’s time. What the trial does not show is any superiority of red 660 nm over infrared 904 nm, so wavelength choice can follow whatever device is available rather than dogma. My bigger caution is structural: there was no true sham or standard-care-only arm, so I genuinely cannot separate the laser’s effect from good wound care plus natural healing, and the endpoint was ulcer area over ten weeks, not complete closure or recurrence. Can I use this with my patients? Only as an adjunct, never instead of glucose control, offloading, debridement, and vascular assessment, and if used, dosed at 8 J/cm² or above in non-infected ulcers. Guidelines still call this optional, and I agree pending larger trials with hard healing endpoints.
References
Bezerra Miranda M, Silva Barros AC, Veloso Coelho L, et al. Dose-response and efficacy of 660-nanometer low-level laser therapy in healing diabetic foot ulcers: a randomized, double-blind, clinical trial. Lasers Med Sci. 2025;40(1):399. doi:10.1007/s10103-025-04641-2