Assessing the Safety and Efficacy of Picosecond Alexandrite Lasers in the Management of Melasma: A Systematic Review and Meta-Analysis of Randomised Control Trials.

Melasma is a chronic hyperpigmentation disorder that disproportionately affects women and individuals with darker skin types, leading to a significant psychosocial burden. This meta-analysis aims to evaluate the safety and efficacy of the 755-nm picosecond alexandrite laser (PSAL) compared with conventional therapies in the management of melasma. PubMed, Ovid Medline, Embase, Cochrane Library, and Google Scholar were searched from inception to April 10, 2025, in accordance with PRISMA guidelines. Randomised controlled trials (RCTs) assessing PSAL versus control comparators in adults with melasma and reporting Melasma Area and Severity Index (MASI) or Modified MASI outcomes were included. The review was registered prospectively on PROSPERO (CRD420251022381). Risk of bias was assessed using ROB2. Pooled effect sizes were calculated using a random-effects model. Five RCTs (n = 139 patients) were included. Change in MASI favoured triple combination cream (TCC) over PSAL therapy (MD = 1.82, 95% CI: 1.11, 2.52, I2 = 0%). Post-inflammatory hyperpigmentation was more common in the PSAL group compared to topical creams (OR = 6.86, 95% CI: 1.47, 32.07, I2 = 0%) but had no difference with the Q-switched lasers (OR = 4.09, 95% CI: 0.62, 26.97, I2 = 0%). There was no incidence of hypopigmentation or infection reported. PSAL appears inferior to the TCC in reducing MASI scores. Overall certainty is low due to small, heterogenous trials. Low rates of irreversible adverse events with PSAL may support trials in refractory cases, but long-term RCTs with larger sample sizes are required to evaluate durability and recurrence outcomes.