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Background and Objective: Fractional photothermolysis (FP) lasers have been widely used in treating photo-aged skin, acne scars, and other skin conditions. Although plenty of clinical data have demonstrated the efficacy of the FP laser, only limited histologic studies have been available to observe serial short- to long-term skin responses., Methods: Seven healthy Chinese women received one pass of fractional carbon dioxide laser treatment on the left upper back. Biopsies were taken at the baseline and 4 hours, 1 day, 5 days, 1 month, 3 months, 6 months, and 1 year after the procedure for hematoxylin and eosin stains, immunohistochemical evaluation (for heat shock proteins and elastin), and Verhoeff-iron-hematoxylin stains (for collagen and elastic fiber)., Results: Remarkably greater expression of heat shock protein (HSP)70 could be observed 4 hours after the procedure, which diminished significantly by 3 months, 6 months, and 1 year after the procedure. HSP47 reached its peak expression 1 month after the procedure, especially around microscopic thermal zones, and maintained its high level of expression 3 and 6 months after the procedure. Distinct new formation and remodeling of collagen and elastic fibers could be observed 3 and 6 months after procedure., Conclusion: FP-induced HSP expression and new formation of collagen and elastic fibers lasted as long as 6 months, longer than the previously acknowledged 3 months., (© 2011 by the American Society for Dermatologic Surgery, Inc.)

Objective: To evaluate the efficacy and safety of the low-fluence 1,064-nm Q-switched neodymium-doped yttrium aluminium garnet (QSNY) laser in treating infraorbital dark circles., Participants and Methods: Thirty women with infraorbital dark circles (predominant color dark brown) participated in this open-label study. Participants underwent eight sessions of low-fluence QSNY laser treatment at 4.2 J/cm(2) at 3- to 4-day intervals. A spot size of 3.5 mm was used, with a pulse duration of 8 ns. The melanin deposition in the lesional skin was observed in vivo using reflectance confocal microscopy (RCM). Morphologic changes were evaluated using a global evaluation, an overall self-assessment, a narrow-band reflectance spectrophotometer, and a skin hydration measurement instrument., Results: Twenty-six of 30 patients showed global improvement that they rated as excellent or good. Twenty-eight rated their overall satisfaction as excellent or good. The melanin index indicated a substantial decrease, from 225.84 at baseline to 182.65 (p < .05). RCM results showed a dramatic decrease of melanin deposition in the upper dermis. Adverse effects were minimal., Conclusions: The characteristic finding for dark-brown infraorbital dark circles is melanin deposition in the upper dermis. Treatment of infraorbital dark circles using low-fluence 1,064-nm QSNY laser is safe and effective. The authors have indicated no significant interest with commercial supporters., (© 2011 by the American Society for Dermatologic Surgery, Inc.)