Stratum Corneum Light Confinement: Monte Carlo Verification

Leah DeVos, Gennadi Saiko, Alexandre Douplik, Alexandre Douplik

2025

Abstract

Significance: The epidermis, the outermost layer of the skin, plays a crucial role in protecting the body from UV radiation, chemical substances, and physical trauma. Its top layer, the stratum corneum (SC), consists of dead skin cells with low water content (~20%), creating a refractive index gradient between the SC and underlying tissue. This gradient traps light within the SC layer, but its impact on light propagation in tissues remains largely unexplored. Aim: The study investigates how refractive index variations in the skin influence light propagation in tissues. Approach: Monte Carlo (MC) light transport simulations were performed in media with and without refractive index mismatches. Results: Light confinement in the SC increases the fluence rate by 12-35% compared to underlying tissue, particularly when the underlying tissue has low diffuse reflectance. This effect is most pronounced when the SC thickness exceeds the reduced scattering length (~150-600 μm for visible light). Such thicknesses occur in glabrous skin (palms, soles) and thickened areas like calluses and corns. Conclusions: By comparing MC simulations, we attribute this light confinement to the SC's high refractive index due to its low water content. This stratum corneum light confinement (SCLC) phenomenon may lead to an inaccurate estimation of light distribution, resulting in errors in some skin diagnostic parameters measured via diffuse reflection, such as water and total hemoglobin content, and blood oxygenation.

Paper Citation

in Harvard Style

DeVos L., Saiko G. and Douplik A. (2025). Stratum Corneum Light Confinement: Monte Carlo Verification. In Proceedings of the 18th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 1: BIOIMAGING; ISBN 978-989-758-731-3, SciTePress, pages 397-402. DOI: 10.5220/0013369700003911

in Bibtex Style

@conference{bioimaging25,
author={Leah DeVos and Gennadi Saiko and Alexandre Douplik},
title={Stratum Corneum Light Confinement: Monte Carlo Verification},
booktitle={Proceedings of the 18th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 1: BIOIMAGING},
year={2025},
pages={397-402},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0013369700003911},
isbn={978-989-758-731-3},
}

in EndNote Style

TY - CONF

JO - Proceedings of the 18th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 1: BIOIMAGING
TI - Stratum Corneum Light Confinement: Monte Carlo Verification
SN - 978-989-758-731-3
AU - DeVos L.
AU - Saiko G.
AU - Douplik A.
PY - 2025
SP - 397
EP - 402
DO - 10.5220/0013369700003911
PB - SciTePress