Quantitative evaluation of skin aging with photoacoustic microscopy

Skin aging as a consequence of damage caused by ultraviolet light has attracted attention in the fields of beauty and health care because photoaging accelerates skin aging. However, few practical techniques exist for the quantitative evaluation of such aging. Photoacoustic imaging, a novel modality, can portray differences of tissue characteristics. In this work, to ascertain the appropriate wavelength for skin imaging and effects of the skin aging process on photoacoustic signal intensity, we measured signals from both sectioned and nonsectioned porcine skin tissue samples using photoacoustic microscopy at 440-520 nm wavelengths. Results show higher signal intensity for light of shorter wavelengths in the measurement region and increasing signal intensity with photoaging progress. According to these results, signal intensity reflects the degree of photoaging well. Through these analyses, we demonstrated the feasibility of quantitative skin aging evaluation with a photoacoustic imaging system.