Permanent Makeup Removal from Murine Skin Using 1,064-nm Q-switched Nd:YAG Laser and 694-nm Q-switched Ruby Laser: Comparing the Degree of Removal Following Irradiation at Different Time Points after Application

Abstract

Background: Q-switched lasers have made it possible to remove tattoos without leaving unsightly scars. Objective: Tobdetermine the optimal time for permanent makeup removal using Q-switched Nd:YAG and ruby lasers, we compared the degree of removal and associated histological changes following irradiation at different time points. Methods: Using black ink and a permanent makeup machine, we performed 108 separate permanent makeup applications on rat skin. The 1,064-nm Q-switched Nd:YAG laser (QSNDL) and 694-nm Q-switched ruby laser (QSRL) were used to irradiate the permanent makeup on the day of its application and also 3, 5, 7, 14, and 21 days later. We assessed changes in pigmentation over time at each irradiated site using Mexameterⓡ measurements and skin biopsies. Results: The Mexameterⓡ analysis demonstrated no significant differences in pigment removal among irradiations with QSNDL or QSRL on the day of permanent makeup application or at 3, 5, 7, 14, and 21 days later. Histological analysis demonstrated that permanent makeup pigment migrated from the epidermis to the superficial and mid dermis over time. QSNDL more effectively removed pigment throughout the epidermis and dermis compared to QSRL. Conclusion: For maximum pigment removal efficacy, the melanin index results suggest that laser treatment should be performed on the day permanent makeup is applied. However, from the histological perspective, permanent makeup should be removed approximately 1 week later, at which point the crusts have peeled off and the wound repair process is almost complete. In this study, histological analysis suggested the superiority of treatment with QSNDL to that with QSRL.