Permanent Makeup Removal from Murine Skin Using a 1064 nm Q-switched Nd:YAG Laser: Comparison of the Degree of Removal When Irradiated at Various Time Points after Application / 대한피부과학회지

BACKGROUND: Various Q-switched (QS) lasers, such as ruby, alexandrite or neodymium:YAG (Nd:YAG) lasers, are used to remove tattoos and permanent makeup. To our knowledge, there has been no indication or guideline published for the optimal time for laser-mediated tattoo removal. OBJECTIVE: To set a guideline for the optimal irradiation time for tattoo and permanent makeup removal via 1064 nm QS Nd:YAG (QSND) laser, we compared the degree of tattoo removal and skin histologic changes when the irradiation was employed at different time points. METHODS: Rat skin was marked with 54 artificial permanent makeup marks with black ink using a permanent makeup machine. The marks were irradiated with a 1064 nm QSND laser on the application day, and 3 days, 5 days, 1 week, 2 weeks, and 3 weeks after application. Pigmentation changes were checked over time using a Mexameter(R) and skin biopsy. RESULTS: There was no significant difference in the degree of pigment removal as examined by Mexameter(R) on the day of makeup application compared to 3 days, 5 days, 1 week, 2 weeks, and 3 weeks after application. Histopathologically, the permanent makeup pigments seemed to move from epidermis to superficial and mid dermis with time. The pigments were relatively well removed throughout the epidermis and dermis when the laser was employed 7 days after tattoo application, compared to laser irradiation on the day of application, as viewed histologically. CONCLUSION: Laser removal of permanent makeup is effective on the day of application, as determined by testing pigment levels. However, based on histopathology, it is recommended to use lasers to remove permanent makeup about a week after application, since the wound repair process is almost complete at that time.

Comparison of Wound Repair after Irradiation of Rat Skin with 1064 nm Nd:YAG, CO2, and Er:YAG Lasers / 대한피부과학회지

BACKGROUND: Laser therapy for various skin conditions is one of the most common procedures in dermatology. Recently, several articles described the use of 1064 nm Q-switched Nd:YAG lasers for the treatment of benign skin lesions. Such treatment is known to trigger its therapeutic effect through a photoacoustic effect and selective photothermolysis effect. However, only a limited number of articles have dealt with the theoretical base of the photoacoustic effect of the 1064 nm Q-switched Nd:YAG laser. OBJECTIVE: To compare the wound repair process and nonselective tissue heat damage induced by three different laser modalities: the CO2 laser, Er:YAG laser, and 1064 nm Q-switched Nd:YAG laser. METHODS: We irradiated the skin of an albino rat (Sprague Dawley(R), 200~250 g) with CO2, Er:YAG, and 1064 nm Q-switched Nd:YAG lasers. Skin biopsy specimens of the irradiated areas were collected on the first, fifth, and tenth day after laser exposure. For histologic analysis, the specimens were stained with the H&E, Verhoff-Van Gieson, and Masson's trichrome protocols. RESULTS: Compared with other laser modalities, rat skin irradiated by the 1064 nm Q-switched Nd:YAG laser showed the least amount of heat damage and the quickest tissue repair response to the damage. CONCLUSION: A 1064 nm Q-switched Nd:YAG laser with a photoacoustic effect capable of ablating the epidermis and dermis can be a proper treatment modality for the removal of benign skin lesions. The 1064 nm Q-switched Nd:YAG laser may be considered as an alternative treatment option for the treatment of benign skin lesions.