Quantitative evaluation of enhanced laser tattoo removal by skin optical clearing

Abstract

Lasers have been widely used for tattoo removal, but the limited light penetration depth caused by high skin scattering property restricts the therapeutic outcome of deep tattoo. Skin optical clearing method, by introducing optical clearing agent (OCA) into skin, has shown some improvement in the e®ect of laser tattoo removal. In this study, the enhanced laser tattoo removal has been quantitatively assessed. OCA was applied to the skin of tattoo animal model and Q-switched Nd:YAG laser (1064 nm) irradiation was used to remove the tattoo. The skin evaluation instrument (Mexameter probe, MPA580) was applied to measure the content of tattoo pigment before and after laser treatment, and then the clearance rate of pigment was calculated. Further, Monte Carlo (MC) method was utilized to simulate the e®ect of skin optical clearing on light transmission in tattoo skin model. By comparing the pigment change of tattoo areas respectively treated with OCA plus laser and single laser, it was found that pigment clearance of the former tattoo area was increased by 1.5-fold. Further, the MC simulation veri¯ed that the reduced light scattering in skin could increase the e®ective dose of luminous°ux reaching to the deep tattoo regions. It can be concluded from both experiment and theoretical This is an Open Access article published by World Scienti¯c Publishing Company. It is distributed under the terms of the Creative Commons Attribution 3.0 (CC-BY) License. Further distribution of this work is permitted, provided the original work is properly cited. k Corresponding Authors. Vol. 8, No. 3 (2015) 1541007 (8 pages simulations that skin optical clearing technique could improve the outcome of laser tattoo removal, which should be bene¯cial for clinical laser tattoo removal and other laser pigment elimination. Journal of Innovative Optical Health Sciences

Skin optical clearing potential of disaccharides

“…15,16,20 Therefore, skin optical clearing has attracted much attention. 4,15,16,[20][21][22][23] Various skin OCAs have been screened out based on experiments, including glycerol, dimethyl sulphoxide (DMSO), oleic acid, polyethylene glycol, butanediol, sorbitol, xylitol, glucose and fructose, and so on. 3,[24][25][26] Khan et al 27 proposed an optical clearing potential (OCP), the ratio of reduced scattering coefficient before and after treatment of OCAs, to evaluate the optical clearing efficacy of skin.…”

Quantitative Monitoring of Tattoo Contrast Variations after 755-nm Laser Treatments in In Vivo Tattoo Models

“…Clinical research on tattoo treatment has used clinical scoring rates to identify any reduction in treated tattoos [5,9,[11][12][13][14]19,20]. However, clinical assessment could be subjective and non-quantitative, because the scores are given by medical experts or blinded researchers.…”

“…However, clinical assessment could be subjective and non-quantitative, because the scores are given by medical experts or blinded researchers. As an alternative method, quantitative evaluations using animal models were developed [5,9,20]. A study evaluating the laser effect on Hartley guinea pigs with multi-colored tattoos used a colorimeter to measure any changes in pigmentation [9].…”

“…However, the calculation of absorbance was still complex, and the method merely showed the total reduction between pre-and post-treatment, whereas the proposed method could monitor the variations in tattoo contrast, even during wound healing. Another study using rat models reported the application of a skin assessment instrument to determine the pigment contents before and after the laser treatment and to estimate the clearance rate [20]. However, the quantitative measurement required a process wherein the instrument was tightly applied to the animal skin in a vertical direction.…”

Research Techniques Made Simple: Optical Clearing and Three-Dimensional Volumetric Imaging of Skin Biopsies

“…In vivo, OTC has been applied to the skin for visualizing blood flow in the skin (Vargas et al, 2003;Wang et al, 2013aWang et al, , 2013bZhu et al, 2010) and cutaneous vascular permeability in mice suffering from diabetes (Feng et al, 2019) and for improving the imaging of diseased skin in a variety of skin diseases such as hemangioma and epidermoid cyst (Shan et al, 2012) as well as increasing laser penetration into the dermis during tattoo removal (Liu et al, 2015).…”