Effect of Fluorescence Biomodulation on Dermal Healing in an Equine Experimental In Vivo Wound Model.

Overview

• This study investigated whether fluorescence biomodulation (FBM) affects the healing process of full-thickness wounds on horse limbs.
• The researchers compared wound healing between wounds treated with FBM and untreated control wounds over a 31-day period, using both visual and microscopic assessments.

Study Purpose and Background

• Objective: To evaluate the safety and impact of fluorescence biomodulation on dermal wound healing.
• Model: Full-thickness wounds were created on the distal limbs (forelimbs) of adult horses.
• Rationale: Horses often develop skin wounds that heal slowly, and novel therapies like FBM could potentially improve this healing process.

Methodology

• Subjects: Six adult horses participated in the study.
• Wound Creation: Two full-thickness wounds were created on each dorsal metacarpus (top of the forelimb) per horse, totaling 24 wounds.
• Treatment Allocation:
  • Each forelimb randomly assigned as either treatment (FBM applied) or control (no treatment).
  • Within each group, wounds were also chosen randomly for visual or histological assessments.
• FBM Treatment:
  • Wounds in the treatment group received FBM twice in each weekly treatment period, for four weeks total.
  • Control group wounds did not receive any FBM.
• Data Collection:
  • Wound surface area was photographed and measured on days 3, 10, 17, 24, and 31.
  • Granulation tissue—a key stage of wound healing—was visually graded.
  • Punch biopsies were taken at multiple time points to assess histological (microscopic tissue) changes.
  • Baseline skin samples were collected from day 0 wound sites before treatment.
• Data Analysis:
  • Linear mixed model statistical methods were used to analyze differences between treated and control wounds over time.

Results

• No statistically significant differences found between FBM-treated and control wounds regarding:
  • Wound surface area reduction (p = 0.755)
  • Composite wound healing scores (p = 0.593)
  • Histological assessment of tissue repair (p = 0.378)
• One horse developed excessive granulation tissue (proud flesh) in all wounds that required surgical debridement at the end of the study.

Interpretation and Implications

• FBM treatment neither improved nor impaired the healing of full-thickness wounds on horse limb skin in this study.
• Possible reasons no treatment effect was detected include:
  • Small sample size (only 6 horses), limiting statistical power.
  • Potential insensitivity of the measured outcome variables to detect subtle changes.
  • Species-specific responses; equine wound healing physiology may differ from other species where FBM might be effective.
• Exuberant granulation tissue in one horse may indicate individual variability or a reaction unrelated to FBM.
• Recommendations:
  • Future studies with larger sample sizes and possibly different outcome measures are necessary to better understand FBM’s effects on horse wound healing.
  • Consider testing FBM on different types of wounds or species to explore its therapeutic potential further.