Quantitative Evaluation of Skin Surface Roughness Using Optical Coherence Tomography In Vivo

The quantitative monitoring of skin topography is important in the field of cosmetics and dermatology. The most widespread method for determining skin roughness in vivo is to use skin microrelief, PRIMOS device, which allows a noninvasive, fast, and direct measurement of the skin surface. However, it has drawbacks, such as the interference of backscattering from volumetric skin and motion artifacts. In this study, we demonstrate the potential of optical coherence tomography (OCT) for providing reliable and quantitative skin surface roughness. In order to evaluate the performance of OCT for skin surface analysis, different types of skin phantoms are fabricated and measured. We utilize OCT to identify the effect of cosmetics as well as human skin topology for various aging groups and different skin regions. Skin surface roughness parameters based on ISO 25178 part 2 standard definitions are then derived from home-built image processing software and compared with one acquired from PRIMOS. Our results show that skin surface geometry acquired from three-dimensional OCT images is well quantified to complex wrinkle structure and robust to the angle of the subject. Since OCT enables to present quantitative skin topology and volumetric skin anatomy simultaneously, it would be a useful tool to deliver comprehensive and intuitive information in dynamic skin observations.