Fractional Laser Resurfacing Treats Photoaging by Promoting Neocollegenesis and Cutaneous Edema.

Laser resurfacing is a common treatment for photoaging. This treatment creates skin incisions that initiate the wound healing cascade, including reorganization of the collagen matrix, in a dermal remodeling process that can last up to 12 months. We compared the effects of nonablative and ablative Erbium fractional laser resurfacing on dermal content and arrangement of Collagen Types I and III, and on fibroblast activation. Ten female patients (50-63 years) with Fitzpatrick Skin Types I-IV and clinical signs of photoaging underwent two types of Erbium fractional laser resurfacing (nonablative, 1540nm; ablative, 2940nm) on opposite sides of the face. Skin biopsies were obtained pretreatment and three months post-treatment. Morphometric analysis was performed using Picrosirius staining for overall collagen, and immunohistochemistry for Collagen Types I and III. Finally, hematoxylin and eosin staining was used to identify fibroblast activation. Both laser treatments induced reorganization of Collagen Types I and III and demonstrated signs of fibroblast activation. However, morphometric analysis of Picrosirius staining revealed that, after both treatments, there was a lower density of collagen fibers, which is characteristic of edema. At three months after laser resurfacing, skin lifting in photoaged skin likely resulted from new collagen deposition but also from edema.