The effect of different doses of 660 nm laser therapy on open skin wound healing in Wistar rats


The study aim to evaluate the effect of 660nm wave length low level laser therapy (LLLT) at different doses on open wound healing in rat model. Twenty five adult male Wistar rats were randomly divided into five equal groups. Rats were anesthetized by IM injection of ketamine (50mg/kg B.W), xylazine (10mg/kg B.W) mixture. The back of animal was prepared for aseptic surgery, two parallel circular skin incisions 0.5 cm in diameter involving full thickness of the skin were made on both left and right sides of the back of each animal. Four groups were received a close-contact pulsed Gallium-Aluminum Arsenide (GaALAs) laser therapy on the left incision, with energy density of 2, 4, 6 and 8J/cm2 of 660nm wave length, 50mw power output and 146Hz pulsing rat immediately after surgery then repeated the same dose daily for 7 successive days. Results declare that the laser treated group of 2J/cm2 found slightly differences when compared with control group. At 4J/cm2 laser treated group, the healing of wound was better than of control group by presence of narrow scar tissue and completely epithelization. The study found that 6J/cm2 laser treated group was effective in open wounds, which showed faster keratinize layer formation and collagen fiber parallel oriented with the wound surface. However, energy density of 8J/cm2 was more effective for healing process than other groups by presence of more collagen deposition, increase activity of myofibroblast, and presence of clear skin adnexa. In conclusion, the laser wave length 660 nm use in this study was effective enhance the healing process of open skin wound in rats in all the four energy density used; further to the 8J/cm2 is seen the best in stimulation of wound healing.