Efficacy and safety of low-fluence 1064 nm picosecond laser with/without micro-lens arrays for melasma treatment: a randomized, split-face controlled study.

Low-fluence picosecond (LFPS) neodymium-doped yttrium aluminum garnet (Nd: YAG) 1064 nm laser has emerged as a promising treatment for melasma; however, its optimal strategy remains unclear. To evaluate the efficacy and safety of LFPS combined with microlens arrays (MLA) compared with LFPS alone in treating melasma. Thirty patients with melasma received LFPS alone on one side of the face (control [C] side) and LFPS with MLA on the other (treatment [T] side). Treatments were performed at four-week intervals for five sessions. Standardized imaging, VISIA-CR, and assessments using the Physician's Global Aesthetic Improvement Scale (P-GAIS) and the Melasma Area and Severity Index (MASI) score, were performed at baseline, and at one-, three-, and six-months post-treatment. Recurrences and adverse effects were recorded. MASI scores significantly reduced at all time points compared with baseline (ΔMASI: 3.23, 3.35, and 2.98, respectively). The P-GAIS assessment showed that 3 patients rated 1 point, 5 rated 2, 14 rated 3, and 8 rated 4. No significant adverse events occurred. At six months, recurrence was lower on the T side than on the C side (1 vs. 6 patients; p< 0.05). VISIA-CR analysis showed significant spot reduction on both sides, with no statistically significant difference (p>0.05). Additionally, texture and pore metrics improved on the T side, whereas no significant changes were observed on the C side. LFPS with MLA improved melasma severity, reduced recurrence rates, and enhanced skin texture and pores compared with LFPS alone, offering a safe, effective treatment option.