Evaluation of photoaging in facial skin by multiphoton laser scanning microscopy

BACKGROUND/PURPOSE: It has been reported that autofluorescence (AF) and second harmonic generation (SHG) generated in the upper dermis are related with skin photoaging. In this study, we assessed the photoaging of facial skin exposed to daily sunlight using in vivo multiphoton laser microscopy to measure AF and SHG. METHODS: The intensities of AF and SHG in the upper dermis of cheek skin of 56 healthy volunteers aged 20-69 years were measured using a commercially available multiphoton laser microscope (DermaInspect(®) ). Correlations between the photo-signals and volunteer age were calculated. RESULTS: The intensity of SHG and the SHG-to-AF aging index of dermis (SAAID) correlated significantly with age (r=-0.48, -0.67, respectively). CONCLUSION: Our results suggest that SHG and the SAAID index are useful indicators of facial skin aging in vivo.