In Vitro and In Vivo Laser Treatments of Tattoos

Abstract

Objective:To analyze the absorption of tattoo inks related to their in vivo and in vitro behavior under laser irradiation to improve laser-assisted tattoo removal. Design:The absorption of 21 tattoo inks in a wavelength range from 300 to 800 nm was characterized by reflection spectroscopy from samples consisting of inks mixed in gelatin. Tattoo inks were removed in vitro using pulsed laser radiation with different variables, and morphologic analysis of the irradiated areas was performed.Setting: An interdisciplinary laser laboratory with a common industrial project with the Spanish company Milesman S.A.Participant: One person was voluntarily tattooed with 2 of the studied inks. Main Outcome Measures:(1) First approach to the optimum dose for pigment removal in in vitro models.(2) Correlation between the in vitro and in vivo situations at the optimum dose.Results: Reflection spectroscopy facilitated selection of the most adequate laser wavelengths for tattoo removal. Red, orange, and rose inks were successfully lightened at 532 nm with 0.6 J/cm 2 ; brown at 1064 nm with 0.3 J/cm 2 ; yellow and green at 448 nm with 2.6 J/cm 2 ; and blue at 600 nm with 0.9 J/cm 2 . Similar colors in in vitro and in vivo tattoos responded with the same efficiency to the laser variables.Conclusions: High efficiency is reached in the removal of in vivo tattoos by using an irradiation wavelength at which the percentage of reflection from the pigment is minimal. Under this condition, laser pulses can be used with a low fluence, minimizing adverse effects and clinical time.

Feasibility of LED-Assisted CMOS Camera: Contrast Estimation for Laser Tattoo Treatment

“…Owing to the different characteristics of light absorption [5,11,13], the After the tattoo areas had completely healed (14 days), each mouse received a laser tattoo treatment under anesthesia. Owing to the different characteristics of light absorption [5,11,13], the black and red tattoos were removed using Q-switched 1064-nm and 532-nm wavelengths, respectively (Iris, Bluecore Company, Busan, Korea). The laser conditions for the tattoo treatment included a spot size of 5 mm on the skin, a pulse duration of 8-10 ns, and a repetition rate of 1 Hz.…”

“…The aiming beam was precisely aligned and positioned on half of the tattoo band prior to the treatment. Based on the previous in vivo studies [5,11,13], fluences of 1.5 J/cm 2 and 0.5 J/cm 2 were selected for removing the black and red tattoos, respectively. Table 1 shows a summary of the laser parameters used for the current study.…”

“…Unlike surgical excision, the laser removal method delivers various wavelengths, selectively targets the particular tattoo pigments, and then fragments the pigment into small particles using short pulsed laser light [10][11][12]. These fragments are then removed from the skin through the lymphatic system or trans-epidermal elimination [13,14]. In addition, the targeted tattoo pigments specifically absorb laser light with no or minimal injury to the surrounding healthy tissue.…”

“…In addition, the targeted tattoo pigments specifically absorb laser light with no or minimal injury to the surrounding healthy tissue. Thus, the method can reduce pain, treatment time, and complications [2,8,13].…”

“…Thus, it was hypothesized that a CMOS camera with cost-effective and small-sized LED sources could be a feasible imaging tool to estimate the contrast variations in the tattooed skin after a laser treatment [20,21]. Furthermore, because the laser-treated tattoo can be removed through the lymphatic system or trans-epidermal elimination [13,14], the current study evaluated the proposed device in vivo to emulate clinical conditions.…”