Evaluation of procollagen I deposition after intense pulsed light treatments at varying parameters in a porcine model.

Several lasers and light sources have been reported to induce dermal collagen remodeling without damaging the epidermis. The intense pulsed light (IPL) system, which emits polychromatic light of wavelengths between 560 and 1200 nm belongs to this group of increasingly popular non-ablative skin rejuvenation devices. Various IPL treatment parameters can be adjusted to achieve optimal dermal remodeling and clinical improvement. The aim of this study was to evaluate variations in IPL treatment parameters and the effect on procollagen I deposition. Marked areas of a live Yorkshire pig's flank skin were irradiated with a single or double pass of an IPL source using a fluence of 30 or 40 J/cm2 and a cut-off wavelength filter of 590 nm. Skin biopsies were performed on postoperative days 1, 7, 14, 21, and 42. A statistically significant increase in procollagen I in treated versus untreated sites was found on postoperative days 21 and 42, but not earlier. There was a uniformly significant increase in procollagen I on day 42 using the 590 nm filter at both 30 and 40 J/cm2 with either a single or double pass. The increase in procollagen was greater with a fluence of 40 J/cm2 compared with 30 J/cm2.