Effects and parameterization of low-level laser therapy in diabetic ulcers: an umbrella review of systematic reviews and meta-umbrella.

This study aimed to systematically verify the available systematic reviews and meta-analyses of Low-level laser therapy (LLLT) in diabetic foot ulcer (DFUs) to identify the effects and optimal parameters of LLLT in the management of DFUs. This umbrella review was written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) report items and registered in the International Prospective Register of Systematic Review (PROSPERO). The search for articles was performed in the Pubmed, Scopus, Web of Science and Embase databases. The following terms were used: Diabetic Foot, Diabetic Neuropathies, Peripheral Vascular Diseases, Peripheral Neuropathy, Diabetic Foot Ulcer, LASER Therapy, Low-Level Light Therapy, LLLT, LASER Biostimulation, Low Intensity LASER Irradiation, Low Power LASER Irradiation, Low Intensity LASER Therapy, Low Power LASER Therapy. A search was performed in the references section of the included studies. The systematic review (SR) included studies that compared LLLT with non-therapeutic doses (parameters considered low to modify healing), sham irradiation, and conventional DFU treatment. The interventions were performed using red and infrared wavelengths. Although two studies included in the SR used wavelengths below 600 nm, these were combined with diodes with infrared wavelengths within the same device. Another study performed a comparative analysis of LLLT at different wavelengths (632 nm and 904 nm), with area reduction rates of 63.7% and 56.8%, respectively, with no statistically significant difference. This is study indicated that, compared with standard treatment and non-irradiation treatments, the use of photobiomodulation (PBM) with different parameters was effective in promoting UPD healing. Further studies are warranted to determine the ideal parameters for improving patient outcomes. (International Prospective Register of Systematic Review Registration number: CRD42022362447).