A split-face, evaluator-blind randomized study on the early effects of Q-switched Nd:YAG laser versus Er:YAG micropeel in light solar lentigines in Asians

Background: Asians are prone to develop epidermal pigmentary lesions as a result of photoaging. Solar lentigines, especially those which are light in color, show somewhat limited response to pigment lasers and intense pulsed light sources. Objectives: We sought to compare the early effects as well as side effects of Q-switched Nd:YAG and Er:YAG micropeel in treating light solar lentigines in Asians. Patient and methods: This was a split-face, evaluator-blind, randomized controlled study. A single session of treatment was performed on Asian patients with light facial lentigines. Q-switched Nd:YAG laser was allocated to one half of the face, and Er:YAG micropeel to the other half. The response to therapy was evaluated by two independent dermatologists with standardized photographs taken 2 weeks and 1 month after the laser treatment. Patients' satisfaction and preference in treatment were also assessed. Results: Fifteen patients completed the study and were analyzed. A reduction in pigment was observed with both lasers during the study period. The degree of pigment reduction in the Q-switched Nd:YAG treated side of the face was significantly higher than that of the Er:YAG micropeel treated side at 2-week follow-up (p < 0.001). The degree of pigment reduction between the Q-switched Nd:YAG-treated side and the Er:YAG micropeel-treated side was similar at 1-month follow-up (p = 0.110). Conclusion: While there is no perfect therapy for light solar lentigines, a single session of Q-switched Nd:YAG laser and Er:YAG micropeel was shown to reduce pigmentation. The immediate effects (2-week follow-up) were better with the Q-switched Nd:YAG laser but there was no great difference between the two laser types at 1-month follow-up due to the greater degree of post-inflammatory hyperpigmentation following Q-switched Nd:YAG. Both laser types could be applied either singly in turns, or in combination for maximal efficacy in future.