Effect of low-dose argon irradiation on rate of wound closure

Four open circular wounds were made on the backs of each of ten guinea pigs by excising approximately 2-cm areas of full-thickness skin and subcutaneous tissue. Every 2 or 3 days, one of the four wounds was treated with 2 J/cm2 argon laser, one washed and treated, one only washed, and one receiving no treatment. The area of the remaining open wound was traced on a glass microslide. A tenth guinea pig received the same "treatments" but the laser was not turned on. The wounds receiving different treatments were randomly selected on different guinea pigs. The area of open wound remaining was measured with a planimeter, and the rate of healing was plotted for each. The numbers of days required for 50 and 75% healing were determined. All wounds were coded and the results determined by an independent observer. We found no difference in the rate of healing of any of these wounds and, under these experimental conditions, found no effect on the overall rate of wound healing by low-dose argon laser exposure.