Effect of helium‐neon and infrared laser irradiation on wound healing in rabbits

TLDR

The study investigated the biostimulating effects of HeNe, pulsed IR, and their combination on skin wound healing in New Zealand white rabbits. Seventy‑two rabbits were assigned to four groups—no exposure, HeNe alone, pulsed IR alone, or combined HeNe and IR—and received daily irradiation for 21 days, with wound areas photographed and tissue samples analyzed for tensile strength, epidermal thickness, and collagen area. Laser irradiation at 632.8 nm and 904 nm, alone or combined, significantly increased tensile strength of treated wounds and also enhanced tensile strength in the contralateral non‑irradiated wound, while having no effect on wound healing rate or collagen area.

Abstract

Abstract We examined the biostimulating effects of helium‐neon laser radiation (HeNe; 632.8 nm), pulsed infrared laser radiation (IR; 904 nm), and the two combined on skin wound healing in New Zealand white rabbits. Seventy‐two rabbits received either (1) no exposure, (2) 1.65 J/cm 2 HeNe, (3) 8.25 J/cm 2 pulsed IR, or (4) both HeNe and IR together to one of two dorsal full‐thickness skin wounds, daily, for 21 days. Wound areas were measured photographically at periodic intervals. Tissue samples were analyzed for tensile strength, and histology was done to measure epidermal thickness and cross‐sectional collagen area. Significant differences were found in the tensile strength of all laser‐treated groups (both the irradiated and nonirradiated lesion) compared to group 1. No differences were found in the rate of wound healing or collagen area. Epidermal growth was greater in the HeNe‐lased area compared to unexposed tissue, but the difference was not significant. Thus, laser irradiation at 632.8 nm and 904 nm alone or in combination increased tensile strength during wound healing and may have released tissue factors into the systemic circulation that increased tensile strength on the opposite side as well.