Effects of low-level energy lasers on the healing of full-thickness skin defects

Effects of low-level helium-neon laser radiation were compared on (1) wounds that closed primarily by contraction and (2) the breaking strength of straight-line incisions. Circular full-thickness skin defects in rabbits received dosages of 1.1 J/cm2 during a 30-min exposure every third day, and 2.2 J/cm2 during a 3-min exposure twice daily until wound closure. No significant differences in healing were observed between laser-treated wounds and untreated control wounds. Conversely, rat skin incisions exposed to 2.2 J/cm2 for 3 min twice daily for 14 days demonstrated a 55% increase in breaking strength over control rats (p less than 0.01); 28 days postoperatively, this difference in breaking strength diminished to a nonsignificant 16% increase over the control rats. Increasing the dosage to 4.5 J/cm2 yielded a nonsignificant 17% increase over the control rats 14 days postoperatively. HeNe laser irradiation of wounds increases certain aspects of healing in the early stages, but not to such a degree as to be clinically applicable. More detailed research is indicated to obtain optimal exposure levels necessary to accelerate wound healing significantly.