Objective evaluation of the effects of intense pulsed light treatment on Asian skin by reflectance confocal microscopy analysis

This study aimed to evaluate the effect of IPL treatment on Asian skin by reflectance confocal microscopy (RCM) analysis. Ten Asian female volunteers (39~54 years old, Fitzpatrick skin type III~IV) received five monthly IPL treatments. RCM skin images were evaluated, and several skin physiological parameters including thickness of stratum corneum, minimal thickness of epidermis, thickness of basal layer, density of dermal papillae, and mean diameter of papillae capillaries were measured both at baseline and 1 month after the last treatment. Transepidermal water loss (TEWL) was evaluated, as well. Thickness of stratum corneum was 4.80 ± 1.48 μm before IPL treatment and 5.50 ± 1.35 μm after treatment (p = 0.322). Both minimal thickness of epidermis and thickness of basal layer were significantly increased (p = 0.002 and 0.018, respectively) after IPL treatment. Dermal papillae density was significantly increased (p = 0.035), whereas mean capillary diameter was reduced significantly (p = 0.035). TEWL was slightly increased after treatment, while the difference was not significant on either T-zone or U-zone (p = 0.085 on T-zone and p = 0.114 on U-zone). RCM imaging is a feasible method to evaluate the effect of IPL effect on human skin. Moreover, IPL treatment serves to be highly safe in skin rejuvenation.