Effects of a low level laser on the acceleration of wound healing in rabbits

BACKGROUND: Tissue healing is a complex process that involves local and systemic responses. The use of low level laser therapy for wound healing has been shown to be effective in modulating both local and systemic response. AIM: The aim of this study was to accelerate and facilitate wound healing and reduce scar formation and wound contraction of an open wound by a low level laser. MATERIALS & METHODS: Twenty adult male rabbits, lepus cuniculus demostica, were brought from a Basrah local market and raised under proper management conditions in Basrah Veterinary Medicine College. The age of these rabbits ranged between 8-10 months and their body weight was 1.5-2 Kg. The rabbits were divided into two groups, group I (Control) and group II (Treated). General anesthesia was provided by a mixture of Xylazine and Ketamine at a ratio of 1:0.5m intramuscularly. Selected sites were shaved, cleaned and disinfected. A wound of 4-cm length and 3-cm depth was made on the gluteal region; six hours later, the wound was treated with gallium aluminum and an arsenide diode laser with a power output of 10m at a wavelength of 890nm in pulsed nods, with a frequency of 20 KLTZ. The wound exposure to the laser was once a day at 890 nm wavelength for 5 minutes over a 7-day period. Histopathological study was obtained regarding the wound depth and edge of the skin on the 3(rd), 7(th) and 14(th) days. RESULTS: The histopathological finding of group I at three days postoperative showed hemorrhage with inflammatory cell infiltration, mainly neutrophils as well as congested blood vessels in the gap. At seven days, the gap contained necrotized neutrophils together with hemolysis and granulation tissue under the dermis tissue. Hemolysis was seen between the muscle fibers. At 14 days, there was irregular fibrous connective tissue proliferation with congested blood vessels seen in the gap with mononuclear cell infiltration. In group II at three days postoperative, severe inflammatory cell infiltration was observed, mainly neutrophils with proliferation of fibroblasts from a few fibrous connective tissues. On the 7(th) day, the main lesion was characterized by severe granulation tissue that consisted of proliferation of fibrous connective tissue and congested blood vessels in the gap of the incision with mononuclear cell infiltration. CONCLUSIONS: The study found that low level laser therapy (II) was effective in open wounds, which showed better regeneration and faster restoration of structural and functional integrity as compared to the control group.