Correlations of light scattering properties in human skin with the person's age assessed using a non-invasive technique.

We analyze the influence of a person's age on the thicknesses and reduced scattering coefficients of the epidermis and dermis in visible part of the spectrum. Their values were assessed using a non-invasive technique which combines pulsed photothermal radiometry and diffuse reflectance spectroscopy with Monte Carlo modeling of light transport in a four-layer model of skin. The analysis is affected by the strong influences of the melanin content on the reduced scattering coefficient of the epidermis, a epi , and blood content in the case of dermis ( a der ). Separating their contributions reveals a significant decrease of a der with the person's age at an average rate of -0.25 mm -1 per decade, while the contribution of blood in the papillary dermis amounts to 1.0 mm -1 % -1 . Meanwhile, no influence of the person's age was found on a epi and the thicknesses of the epidermis or dermis.