Effects of Transcutaneous Photobiomodulation on Diabetic Foot Ulcers.

Effects of Transcutaneous Photobiomodulation on Diabetic Foot Ulcers: A Randomized Clinical Study Monitored by Dark-Field Microscopy and Infrared Thermography

Foot ulcers in people with diabetes mellitus represent one of the most serious chronic complications of the disease, being associated with persistent inflammation, high oxidative stress, microvascular dysfunction and systemic hemorheological changes that compromise the progression of the healing process. Given the pathophysiological complexity of these injuries, therapeutic strategies capable of acting simultaneously on the local wound microenvironment and the systemic biological environment become relevant for optimizing tissue repair. This study aims to evaluate the effects of the association between transcutaneous vascular photobiomodulation (FBMVT) and topical photobiomodulation (FBMT) in people with diabetes and foot ulcers. This is a randomized, controlled and prospective phase II clinical trial, with a sample of 20 participants allocated to experimental groups that will receive a standard dressing with neutral healing matrix (TLC) or a protocol combining FBMVT and FBMT. FBMVT will be performed with a 660 nm laser, 100 mW power, continuous mode and 180 J per application, monthly for 12 weeks, totaling four sessions. FBMT will be performed with a 660 nm laser, 100 mW power, 2 J energy per point, twice a week during dressing changes, totaling approximately 24 sessions throughout follow-up. The primary outcome will be the reduction in the area of the lesion (cm²), measured using a standardized planimetric method. As secondary outcomes, the Pressure Ulcer Scale for Healing (PUSH) score will be evaluated, the standardized infrared thermographic assessment of the monthly perilesional region of all participants and the qualitative analysis of peripheral blood by dark field microscopy (MCE) pre and post FBMVT of the intervention group. The data will be analyzed using repeated measures ANOVA, after evaluating the normality of the data, adopting a significance level of 5%. It is expected to observe a reduction in the lesion area, improvement in clinical healing scores, favorable changes in the hemocirculatory dynamics observed in ECM and modulation of thermal patterns related to tissue perfusion, indicating that systemic and local biophotonic modulation can contribute to the optimization of the healing process in foot ulcers in people with diabetes.

Inclusion Criteria:

• Medical diagnosis of Diabetes Mellitus type 1 or 2;
• Presence of a foot ulcer with duration ≥ 4 weeks, characterizing a chronic ulcer;
• Age ≥ 18 years;
• Ankle-brachial index compatible with adequate perfusion, allowing for the safe conduct of treatment;
• Wagner Grade I or Wagner Grade II classification of DM ulcer
• Ability to understand the objectives of the study and signature of the ICF (Informed Consent Form). -

Exclusion Criteria:

• Having more than one ulcer to be treated, regardless of etiology;
• Presence of hematological diseases that may interfere with peripheral blood analysis, such as: hemolytic anemias, hemoglobinopathies (sickle cell anemia), leukemias, lymphomas, multiple myeloma, or other blood dyscrasias that may significantly interfere with cell morphology or peripheral blood analysis;
• Active systemic infection at the time of enrollment;
• Active neoplasia undergoing treatment or under investigation;
• Use of immunosuppressants or corticosteroids;
• Pregnant or breastfeeding women;
• Use of photosensitizing medications;
• Allergy or sensitivity to any of the study interventions;
• Clinical signs of infection, necrosis, devitalized tissue, or wound colonization.
• Acute clinical conditions that contraindicate participation, whether related or unrelated to DM.