35406 Characterization of photodamaged skin using 3D line-field optical coherence tomography and histopathologic correlation

Abstract

Noninvasive imaging techniques morphologically characterize photoaging and generate qualitative analysis in photodamaged skin. Optical coherence tomography (OCT) allows a deep laser penetration in the surface, reaching a good quality image of dermis visualization. A new 3-dimensional technology, 3D line field confocal OCT (LC-OCT) has been introduced, allowing a vertical and horizontal reconstruction of the complete skin with cellular resolution. The objective of this study was to observe in an in vivo 3-dimensional mode (3D LC-OCT) the morphologic and cytologic changes of photodamaged skin, to better understand the changes of the different skin layers induced by chronic sun exposure and responsible for chronic sun damage. 9 phototype II-III subjects were included. Dermoscopy and LC-OCT were performed on 2 zones: the sun-damaged area on the dorsal forearm and the non-sun-damaged area on the ventral side of the same forearm. Skin biopsies were obtained from both areas. All metrics were compared as paired data. LC OCT analysis showed increased epidermal thickness (mean: 5.39 μm, P = .0078) and higher number of keratinocytes (mean = 0.997; P = .002) in exposed vs nonexposed areas. The volume of the different keratinocyte layers seemed to be larger in the exposed area. Histology comparisons also showed an increased epidermal thickness on exposed areas. Significant differences were observed for the number of keratinocyte layers that was higher in photodamaged skin. This study provides for the first time a 3D quantitative analysis of photodamaged skin. There was a good correlation with histopathologic evaluation.