Novel 532‐nm Q‐switched Nd: YAG laser for the treatment of melasma and rejuvenation: a prospective, randomized controlled comparison with 1,064‐nm Q‐switched Nd: YAG laser

Background Melasma is a common pigmentary and photoaging disorder. Although various treatments, including 1,064‐nm Q‐switched neodymium‐doped yttrium aluminum garnet (QS‐Nd: YAG) laser toning, are available for melasma, results are often unsatisfactory. Objective We aimed to determine the efficacy and safety of 532‐nm QS‐Nd: YAG laser (shortwave toning) in patients with melasma and facial rejuvenation. Methods Fifty‐two patients were recruited to receive either 1,064‐nm QS‐Nd: YAG laser or 532‐nm QS‐Nd: YAG laser every 2 weeks for 8 sessions and a 2‐month follow‐up visit in a randomized controlled double‐blinded study. The primary outcome measure was the Melasma Area and Severity Index (MASI) score. Dermoscope and high‐frequency ultrasound (HFUS) were used to assess the improvement of melasma and photoaging. Results 532‐nm QS‐Nd: YAG laser achieved significantly higher improvement in the MASI score (P = 0.000). The Dermoscopic melasma score (DMS) displayed significant change and confirmed the improvement. HFUS showed a significant decrease in the thickness of the subepidermal low‐echogenic band (SLEB) and increases in dermal thickness and dermal density in both groups (P = 0.000 for all). The rate of very satisfied responses was significantly higher in the 532‐nm laser group (P = 0.001). There was no significant difference in the visual analog scale pain assessment score (P = 0.248) and recurrence rate (P = 0.734) between the two groups. Conclusion 532‐nm QS‐Nd: YAG laser (shortwave toning) proved to be an effective and safe treatment for melasma and rejuvenation. Shortwave toning was significantly better for pigmentation clearance, while 1,064‐nm laser showed better improvement in skin rejuvenation.