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.

Study Overview

• Status: Recruiting
• Conditions: Diabetes Mellitus; Foot Ulcer
• Intervention / Treatment: Radiation: PBM - Photobiomodulation; Other: Standard Treatment; Radiation: Placebo PBM

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Rebeca B Cecatto, Ph.D.; Phone Number: 11970842496; Email: rebeca.boltes@gmail.com

Study Locations

• Brazil
  • Piauí
    • Teresina, Piauí, Brazil
      • Recruiting
      • Universidade Estadual do Piaui
      • Contact: Rebeca B Cecatto; Phone Number: 11970842496; Email: rebeca.boltes@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: PBM Treatment Group; PBM group	Radiation: PBM - Photobiomodulation; Application of transcutaneous PBM therapy to the foot ulcer Photobiomodulation (PBM)-formerly referred to as low-level laser therapy (LLLT) or cold laser therapy-is a non-invasive, non-thermal therapeutic modality that employs light in the red to near-infrared spectrum (typically spanning wavelengths from approximately 600 nm to 1,100 nm) to elicit beneficial biological responses in target tissues.; Other Names: Low Level Laser Therapy; Other: Standard Treatment; cutaneous standard dressing with neutral healing matrix (TLC); Other Names: Standard dressing with neutral healing matrix (TLC)
Placebo Comparator: PBM Placebo Group; PBM placebo group	Other: Standard Treatment; cutaneous standard dressing with neutral healing matrix (TLC); Other Names: Standard dressing with neutral healing matrix (TLC); Radiation: Placebo PBM; Application of transcutaneous PBM therapy - device switched off-

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Size of wound area	Wound area (cm²). To obtain the wound area, a standardized two-dimensional measurement technique will be used, considering the greatest length (longitudinal axis) and the greatest width perpendicular to the length (transverse axis), with area estimated using the formula: Area (cm²) = length × width This method is widely accepted in clinical practice and clinical studies, especially when combined with evaluator standardization and systematic photographic documentation, and is recommended by international guidelines for longitudinal wound monitoring (IWGDF, 2023; EWMA, 2022).	At the basal assessment (baseline), immediately before the PBM therapy, and after 12 weeks of treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of area reduction over time	percentage (%) reduction from baseline area, as recommended by international consensus guidelines for outcome assessment in chronic wounds (IWGDF, 2023; EWMA, 2022).	At the basal assessment (baseline), immediately before the weekly PBM therapy, and after 12 weeks of treatment
Healing Wound Progression	The assessment of healing progression will be performed using the Pressure Ulcer Scale for Healing (PUSH), developed by Bryant & Nix in 1997 and validated by the National Pressure Ulcer Advisory Panel (NPUAP) (NPUAP, 1998; Bryant & Nix, 1997).	At the basal assessment (baseline), and after 12 weeks of treatment
Pain Intensity	The presence of pain in the cutaneous reference region of the triceps surae will be assessed using a Numerical Pain Scale (NPS) / The NPS is an aid in measuring the intensity of pain felt by the patient, an important instrument to verify progress and analyze the treatment instituted. The participant should be asked about their level of pain, where 0 means total absence of pain and 10 the maximum pain level.	At the basal assessment (baseline), immediately before the weekly PBM therapy, and after 12 weeks of treatment
Wound temperature	Thermographic assessment will be performed using a portable infrared camera (FLIR C5) (Figure 3), with a spectral range of 7.5-14 µm (thermal infrared), thermal resolution of 160 × 120 pixels, sensitivity ≤ 0.05 °C (50 mK), and accuracy of ±2 °C or ±2%. Emissivity was set at 0.98 for adequate representation of the skin surface.	At the basal assessment (baseline), and after 12 weeks of treatment
Blood cell morphology	Blood cell morphology will be assessed using dark-field microscopy methodology.	At the basal assessment (baseline), and after 12 weeks of treatment

Collaborators and Investigators

• Sponsor: University of Nove de Julho

Study record dates

Study Major Dates

• Study Start (Actual): May 12, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): March 1, 2027

Study Registration Dates

• First Submitted: August 28, 2026
• First Submitted That Met QC Criteria: August 28, 2026
• First Posted (Actual): September 2, 2026

Study Record Updates

• Last Update Posted (Actual): September 2, 2026
• Last Update Submitted That Met QC Criteria: August 28, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Skin Diseases; Skin Ulcer; Leg Ulcer; Foot Diseases; Nutritional and Metabolic Diseases; Skin and Connective Tissue Diseases; Diabetes Mellitus; Foot Ulcer; Therapeutics; Laser Therapy; Phototherapy; Low-Level Light Therapy
• Other Study ID Numbers: DMPBMThermo

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No