Prospective Ultramorphological Characterization of Human Hair by Optical Coherence Tomography

This study utilized optical coherence tomography (OCT) to create in vitro cross-sectional images of human hair, specifically focusing on standard Afro-ethnic hair. The research aimed to develop non-invasive techniques for evaluating cosmetic products. The mean diameter of the medulla was found to be 29±7 micrometers, and the hair diameter was 122±16 micrometers. A 3D image was constructed from 601 slices, each taken at 6.0 micrometer steps. The study concluded that OCT could identify key hair structures such as the cuticle, cortex, and medulla. However, after treating the hair with an 18% ammonium thioglycolate solution, these structures were no longer identifiable due to the chemical's damaging effects.