Optical Coherence Tomography Mapping of the Scattering Coefficient to Study the Skin Hydration Process under Optical...

Area of Science:

• Biomedical Optics
• Dermatology
• Medical Imaging

Background:

• Skin hydration is crucial for skin health, but current optical methods lack depth and resolution for comprehensive analysis.
• Assessing skin's response to topical treatments requires advanced techniques for detailed spatiotemporal water dynamics.

Purpose of the Study:

• To develop and validate a novel optical coherence tomography (OCT)-based approach for quantitative assessment of skin dehydration and rehydration.
• To investigate the effects of topical ethanol, betamethasone dipropionate, and ultrasound on skin water content and recovery dynamics ex vivo.

Main Methods:

• Reconstructing the scattering coefficient from OCT data to quantify skin hydration.
• Applying topical agents (70% ethanol, betamethasone dipropionate) and ultrasound (1 MHz, 0.5 W/cm², 2 min) to rat skin ex vivo.
• Analyzing dehydration depth and rehydration time using high-resolution spatiotemporal heatmaps.

Main Results:

• Ethanol induced reversible upper skin layer dehydration (168±88 µm) with rehydration in 21±3 min.
• Ultrasound enhanced ethanol penetration (262±63 µm) and reduced rehydration time (14±3 min).
• Betamethasone dipropionate increased dehydration depth and delayed rehydration.

Conclusions:

• The developed OCT method provides high-resolution quantitative assessment of skin water diffusion.
• This technique effectively evaluates the impact of topical treatments and physical stimuli on skin hydration dynamics.
• The findings have implications for understanding skin physiology, pathology, and treatment efficacy.