In-vivo assessment of cleavage line orientation in human skin using Optical coherence tomography

Collagen and elastin fibers are generally arranged in parallel bundles within the dermis. These bundles are oriented such that they can most efficiently resist the stress and strain that normally occurs on the skin during movement. The pattern of these fiber bundles establishes the lines of cleavage of the skin. Knowledge of the orientation of these is of key importance for surgical procedures. When incisions are cut parallel to the cleavage line orientation the incision will heal better and produce less scaring. In this work we report a novel application of Optical coherence tomography for the determination of cleavage line orientation in in-vivo human skin. The technique operates by pressing a small circular indenter onto the skin to deform the skin. This is then imaged using optical coherence tomography. Analysis of the resulting deformation can be seen to have an ellipsoidal shape which is related to the cleavage line orientation. We demonstrate that the technique can be used to map the cleavage line orientation in-vivo.