Comparison of 755-nm picosecond alexandrite laser versus 1064-nm Q-switched Nd:YAG laser for melasma: A randomized, split-face controlled, 2-year follow-up study

Objectives: Pulsed laser treatment of melasma has shown some promising results. To compare the effectiveness and safety of 755-nm picosecond alexandrite laser (PSAL) fitted with diffractive lens array (DLA) versus 1064-nm Q-switched neodynimum:yttrium aluminum garnet laser (QSNYL) for the treatment of melasma. Methods: We conducted a randomized, split face controlled, 2-year follow-up study. Each face was divided into two parts, each side receiving three treatments with either PSAL or QSNYL at 1 month intervals. Modified Melasma Area Severity Index scores (mMASI), pain scores, patient satisfaction and adverse events were recorded. In vivo reflectance confocal microscopy (RCM) images were acquired. Results: Twenty subjects were enrolled and three dropped out. At 6 months, mMASI scores were significantly lower than baseline for QSNYL sides (p = 0.022), with no statistically significant difference between PSAL sides before and after treatment, PSAL sides versus QSNYL sides, or patient satisfaction scores. QSNYL treatment was associated with less pain (p = 0.014). No serious adverse events were reported. In the PSAL sides RCM showed a large number of dendritic melanocytes infiltrated in the dermis at 2 weeks and 4 weeks after treatment. Ten patients (58.82%) reported recurrence or exacerbation at 2-year follow-up with no statistically significant difference between the two lasers. Conclusions: QSNYL demonstrated short term clinical efficacy for melasma, but did not provide any additional benefit compared to PSAL with DLA. QSNYL was associated with less pain. There was a high recurrence rate at 2-year follow-up. RCM allowed the detection of cellular changes in melasma lesions.