ABSTRACT
The application of optical clearing agents on skin allows the optical properties of skin to be controlled and thus the enhancement of optical probing depth. However, optical clearing agents can affect skin hydration, which is an important parameter critical for maintaining healthy skin conditions.
This chapter aims to review recent progress in the investigation of the influence of optical clearing on water content of the skin using confocal Raman spectroscopy, refractometry, time domain THz spectrometry, and other methods. Firstly, the structure and optical properties of skin and the basic principles of skin optical clearing are discussed. Further, a short review of methods for skin water content assessment, including differential scanning calorimetry, nuclear magnetic resonance spectroscopy, confocal Raman spectroscopy, etc., is presented. Finally, a summary of investigations on changes in the water content of skin after the application of optical clearing agents is presented.
