Effect of intense pulsed light on rat skin.

ABSTRACT

BACKGROUND: Intense pulsed light (IPL) is widely used in treating skin conditions and has been reported to increase collagen and elastic fibers without damaging the epidermis. OBJECTIVE: To evaluate the effect of variation in the number of passes and intervals of IPL treatments on photorejuvenation in rats. MATERIALS AND METHODS: Groups of two rats each were exposed to two or four passes of an IPL source using a fluence of 30 J/cm(2) and a cut-off filter of 560 nm at 1- or 3-week intervals. The collagen and elastic fiber content in stained tissue biopsies and the thickness of the collagen fibers of IPL-irradiated and unexposed skin regions were compared. RESULTS: Collagen distribution and collagen fiber diameter was in IPL-irradiated than in control regions. The number of passes did not significantly affect the collagen fiber thickness, but the collagen fibers from the 3-week-interval groups were thicker than those of the 1-week-interval groups (p < .001). CONCLUSION: IPL increased dermal collagen fibers and collagen fiber diameter, suggesting efficacy in photorejuvenation and wrinkle reduction.