The Efficacy and Safety of a Low-Fluence 1064 nm Picosecond ND-YAG Laser Compared with Those of a Low-Fluence Photoacoustic Therapy Pulsed (PTP) Mode 1064 nm Q-Switched ND-YAG Laser for Treatment of Melasma: A Prospective Split-Face Study

Melasma is a challenging pigmentation disorder to treat, and although low-fluence 1064 nm picosecond ND-YAG lasers have shown potential for treating benign pigmented disorders, data on the use of this laser for melasma treatment are currently insufficient. In this prospective split-face study, twenty-four patients with melasma on the face were enrolled and randomly assigned to receive treatment on one side of the face either with a low-fluence 1064 nm picosecond ND-YAG laser or with a low-fluence PTP mode 1064 nm Q-switched ND-YAG laser. Laser treatment was performed 5 times at intervals of 2 weeks, with evaluation conducted before each treatment and 2 months after the completion of 5 treatments. Clinical pictures using a standardized, digital photographic system and dermoscopy were taken on each day of the visit. The modified melasma area severity index (mMASI), melanin index (MI), dermoscopic scores of the pigmentary and vascular elements in melasma, pain during laser treatment, and patient satisfaction score were recorded. Twenty-one participants completed the study, and from week 2 in both groups, a significant decrease in mMASI and MI were confirmed. Although no statistically significant difference was observed, the decrease in mMASI and MI were greater in the 1064 nm picosecond ND-YAG laser group than in the 1064 nm Q-switched ND-YAG laser group. The 1064 nm picosecond ND-YAG laser group showed significant improvement in the pseudoreticular network and globular pattern of dermoscopic features between week 0 and week 16, while significant improvement in the globular pattern was shown in the 1064 nm Q-switched ND-YAG laser group. No significant difference was observed between the two groups in terms of the patient satisfaction score and pain during laser treatments. Notably, no adverse events were observed in either group. In conclusion, our study demonstrated that a low-fluence 1064 nm picosecond ND-YAG laser is as effective and safe in the treatment of melasma as a low-fluence PTP mode 1064 nm Q-switched ND-YAG laser.