Comparison of line‐field confocal optical coherence tomography images with histological sections: Validation of a new method for in vivo and non‐invasive quantification of superficial dermis thickness

Background Line‐field confocal optical coherence tomography (LC‐OCT) is an imaging technique providing “optical biopsies” of the skin in real time and non‐invasively. At a center optical wavelength of 1.3 µm, this innovative technology can be applied to dermo‐cosmetic product development due to both high image resolution (~2 µm) and sufficient penetration (~0.5 mm). Nevertheless, the precise dermal area analyzed with LC‐OCT has never been identified. In this study, the objective was to compare LC‐OCT images with histological sections of the same area, in order to validate a new method for in vivo and non‐invasive quantification of superficial dermis thickness. Once validated, this standardized and quantitative method was used to assess age‐related changes of the superficial dermis. Materials and Methods Ex vivo LC‐OCT acquisitions and hematoxylin‐eosin‐safran staining were performed on a panel of four healthy Caucasian female volunteers. In vivo LC‐OCT study of skin aging was performed on a panel of 37 healthy Caucasian female divided into five different age‐groups. Results Comparison with histological sections revealed that LC‐OCT images allow the visualization and the quantification of the superficial portion of papillary dermis. Applied to different age‐group of volunteers, LC‐OCT images show a constant decrease in this superficial dermis thickness with age. Conclusions In conclusion, we have introduced LC‐OCT as a novel technique for in vivo and non‐invasive evaluation of superficial dermis thickness. This approach could be used in the future to demonstrate visually and quantitatively the capacity of a dermo‐cosmetic active ingredient to renormalize the structural properties of the dermis.