In the present applications of optical coherence tomography (OCT), parameters besides pure morphology are evaluated in skin tissue under in vivo conditions. Spatially mapped refractive indices and scattering coefficients may support tissue characterization for research and diagnostic purposes in cosmetics/pharmacy and medicine, respectively. The sample arm of our OCT setup has been arranged to permit refractive index evaluation with little mechanical adjustment of a lens within the objective. A simple algorithm has been derived. Known from atmospheric work, the Klett algorithm [J. D. Klett, "Stable analytical inversion solution for processing LIDAR returns," Appl. Opt. 20(2), 211-220 (1981)] has been applied to the same data set for retrieval of scattering coefficients. Both parameters have been measured in layered structures in skin like stratum corneum, epidermis and dermis. Significant water content in a localized sweat gland duct has been observed by refractive index evaluation. Time studies over 1.5 h permitted a first understanding about physiological changes in skin which are not obtainable by intrusive methods.

Besides morphological images created by optical coherence tomography (OCT), further parameters are evaluated in skin tissue under in vivo conditions. Scattering coefficients and refractive indices may support tissue characterization for research and diagnostic purposes in cosmetics I pharmacy and medicine, respectively. The known Klett algorithm'5 has been applied for retrieval of scattering coefficients. To permit refractive index evaluation, the sample arm of our OCT setup has been arranged to minimize mechanical adjustment of a lens within the objective. A corresponding simple algorithm has been derived. Both parameters have been measured in layered structures in skin like stratum corneum, epidermis and dermis. Significant water content in a localized sweatgland duct has been observed by refractive index evaluation.