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

This study aimed to determine the safety and macroscopic/microscopic effects of fluorescence biomodulation (FBM) on experimentally induced, full-thickness, distal limb wounds in horses. This was an in vivo experimental study (n = 6 horses). Two full-thickness wounds were created on both dorsal metacarpi of six adult horses. Each forelimb was randomly allocated to either control (no FBM) or treatment (FBM) and randomly allocated to visual or histological assessment of healing. Wounds were treated within each experimental group every 7 days for four treatments. Fluorescence biomodulation wounds were treated twice per treatment period. Control wounds had no FBM treatment. Wounds were visually assessed for granulation tissue grading and photographed for wound surface area calculation, on days 3, 10, 17, 24 and 31. The skin from wound creation on day 0 was used for histology baseline. The wounds were then punch-biopsied on days 10, 17, 24 and 31. Data were analysed using linear mixed model analyses. Differences between control and treatment were not observed for any time point for wound surface area (p = 0.755), composite wound scores (p = 0.593), or histological assessment (p = 0.378). One horse produced exuberant granulation tissue in all wounds requiring debridement at study completion. Fluorescence biomodulation did not improve nor impair healing in an equine experimental in vivo distal limb wound model. Treatment effects may not have been observed due to small sample size, outcome variables measured or species differences. Further studies are needed.