In-vivo detection of the skin dermo-epidermal junction by ultrahigh resolution optical coherence tomography (Conference Presentation)

The human skin is comprised by two layers; epidermis and dermis, separated by the dermo-epidermal junction (DEJ). The relevance of depicting DEJ and measurement of the epidermal thickness (ET) is e.g. seen for superficial skin cancers where delineation of DEJ is of prime prognostic importance. Another example is diagnosis of psoriasis where a thickened epidermis and a ridged DEJ is a hallmark. Histopathological examination of biopsied tissue is traditionally performed to trace DEJ and measure ET. An efficient and precise method to locate DEJ and measure ET is optical coherence tomography (OCT) which is an in vivo and non-invasive technique. Because of significant changes in the refractive index across the DEJ, it is generally easily resolvable with OCT. However at certain body locations, such as the cheek and in regions of glabrous skin, it is difficult to visualize DEJ since refractive index changes are small. We study the significance of ultrahigh resolution OCT combined with a shadow compensation algorithm in locating the DEJ of the cheek and the palm of the hand of ten healthy volunteers. For the study we use a home-built ultrahigh resolution OCT system and a commercially available OCT system designed for dermatology diagnostic. With this comparative study we conclude on the signal statistics of both dermis and epidermis for the two OCT systems and how the differences of these affect the delineation of DEJ. We finally conclude on the significance of ultrahigh resolution OCT in detecting DEJ and measuring ET.