Analysis of the temporal change in biophysical parameters after fractional laser treatments using reflectance confocal microscopy

Background: Fractional photothermolysis is a popular treatment option for photorejuvenation. Previous literature studies have demonstrated the clinical effectiveness of fractional photothermolysis on cutaneous photoaging; however, the associated changes in biophysical properties of the skin following fractional photothermolysis have not been fully elucidated. This study was conducted to investigate the temporal changes in biophysical parameters after fractional laser treatment on Asian skin. Materials and Methods: Eleven female subjects underwent a single treatment with an erbium glass fractional laser. Skin roughness, elasticity, transepidermal water loss (TEWL), dermal thickness were evaluated before and immediately after treatment and 3 days, 1 week, 2 weeks, and 4 weeks after treatment. The changes in the dermal papilla were analyzed using a reflectance confocal microscopy (RCM). Results: Skin roughness showed the greatest improvement at the first week and net elasticity was most improved at the second week. TEWL and the percentage of melanized and active dermal papillae (DP) were mostly increased for 3 days. At 4 weeks after treatment, the number of total dermal papillae showed a significant increase compared with pretreatment. Conclusion: This is the first study of the characterization and quantification of dermal papilla reflecting the dermal repair process after fractional photothermolysis through an RCM.