Med Lasers.  2021 Sep;10(3):146-152. 10.25289/ML.2021.10.3.146.

The Effect of an Optical Clearing Agent on Tissue Prior to 1064-nm Laser Therapy

• Youn JI

• KMID: 2533521
• DOI: http://doi.org/10.25289/ML.2021.10.3.146

Abstract

Background and Objectives
Although lasers have been widely applied in tissue treatment, the light penetration depth in tissues is limited by the tissue turbidity and affected by its absorption and scattering characteristics. This study investigated the effect of using an optical clearing agent (OCA) on tissue to improve the therapeutic effect of 1064 nm wavelength laser light by reducing the heat generated on the skin surface and increasing the penetration depth.
Materials and Methods
A diode laser (λ = 1064 nm) was applied to a porcine specimen with and without OCA to investigate the penetration depth of the laser light and temperature distribution. A numerical simulation using the finite element method was performed to investigate the temperature distribution of the specimen compared to ex-vivo experiments using a thermocouple and double-integrating sphere to measure the temperature profile and optical properties of the tissue, respectively.
Results
Simulation results showed a decrease in tissue surface temperature with increased penetration depth when the OCA was applied. Furthermore, both absorption and scattering coefficients decreased with the appli cation of OCA. In ex-vivo experiments, temperatures decreased for the tissue surface and the fat layer with the OCA, but not for the muscle layer.
Conclusion
The use of an OCA may be helpful for reducing surface heat generation and enhance the light penetration depth in various near-infrared laser treatments.

Keyword

Laser therapy; Optical clearing agent; Finite element method; Tissue optical property; Temperature distribution