Summary: In a trial in painful diabetic polyneuropathy, low-power laser therapy improved quality-of-life problem scores compared with controls, but the between-group difference in neuropathy severity was not statistically significant, and the authors judged its clinical utility uncertain.
PICO Summary
| Element | Detail |
|---|---|
| Population | 55 patients with diabetic polyneuropathy; randomised controlled trial, Iran. |
| Intervention | Low-power laser therapy (808 and 905 nm; 6 J/cm²), three times weekly for 4 weeks, plus standard care (n=18). |
| Comparison | Low-frequency ultrasound (n=15) or control (n=22), all with standard care. |
| Outcome | All groups reduced Michigan Neuropathy Screening Instrument scores, but the between-group difference was not significant (p=0.292); the laser group’s reduction only approached significance (-2.39; p=0.057). For quality of life, the laser group improved symptom scores (p=0.023) and problem scores (p<0.001), and ANCOVA confirmed a significant group effect for problem scores (p=0.007), with the laser group better than controls (p=0.006). No major adverse effects. The authors concluded clinical utility remains uncertain. |
Low-power laser for diabetic polyneuropathy
RCT · diabetic neuropathy · 4 weeks
Low-power laser improved the QOL-DN problem-score domain versus controls (group effect p=0.007), but the between-group difference in MNSI neuropathy severity was not significant (p=0.292). The authors judged clinical utility uncertain.
Expert Commentary
This is an honest trial whose mixed results should be reported precisely rather than rounded up to a positive headline. The encouraging part is the quality-of-life signal, where low-power laser therapy improved the problem-score domain significantly versus controls, which matters because painful neuropathy erodes sleep, mood, and daily function. The crucial qualifier, which the authors themselves emphasise, is that the neuropathy-severity score did not differ significantly between groups, at p of 0.292, and the laser group’s own change only approached significance, so this is not clear evidence of superior pain or neuropathy reduction. The trial’s value lies in including an active comparator rather than only sham, but the small arms of 15 to 22 patients, short four-week course, unclear blinding for a physical modality, and absence of post-treatment durability data all limit confidence, and the investigators were appropriately cautious in calling clinical utility uncertain. Can I use this with my patients? Only tentatively. For painful diabetic neuropathy refractory to or intolerant of medication, low-power laser is safe and may help quality of life, so it is a reasonable adjunct to try, but I would be candid that it did not significantly outperform comparators on neuropathy severity and would keep glycaemic control and proven symptomatic therapy central.
References
Almasi MH, Mosadeghi N, Safarian A, Almasi PH, Salehi SA, Ebrahimabadi Z, Sadeghi S. Effectiveness of low-power laser therapy and low-frequency ultrasound in reducing pain in patients with diabetic polyneuropathy: a randomized controlled trial. Lasers Med Sci. 2025;40(1):503. doi:10.1007/s10103-025-04720-4