Dermal matrix remodeling after nonablative laser therapy

Objective: Nonablative laser therapy is widely practiced for cutaneous rejuvenation. We sought to quantify dermal molecular changes after exposure of photodamaged skin to nonablative laser energy. Methods: Nonablative laser therapy of forearm skin using either a 585-nm wavelength pulsed dye laser or a 1320-nm wavelength neodymium:yttrium-aluminum-garnet laser was performed. Serial biopsy specimens were obtained at baseline and various times after treatment. Results: Statistically significant increases in type I procollagen messenger RNA expression occurred after exposure of photodamaged skin to each laser. Induction was 47% (P < .05) and 84% (P < .05) above baseline levels 1 week after laser therapy among those treated with the pulsed dye and neodymium:yttrium-aluminum-garnet lasers, respectively. Substantial induction of type III procollagen, various matrix metalloproteinases, and primary cytokines was also demonstrated. Responses with respect to all molecules studied were highly variable. Limitations: This study addresses molecular changes after a single laser exposure whereas clinically, serial treatments are often provided. Conclusions: Nonablative laser therapy may result in quantifiable alterations in molecules associated with remodeling of the dermal matrix, although responses vary greatly among patients.