Picosecond Lasers for Melasma: Systematic Review & Meta-Analysis

Background: Melasma remains one of the most treatment-resistant pigmentary disorders. Picosecond lasers have been proposed as a lower-risk alternative to Q-switched nanosecond devices, but pooled efficacy and recurrence data are lacking. Objective: To systematically review and meta-analyze randomized and controlled trials of picosecond 755 nm and 1064 nm lasers for facial melasma. Methods: PubMed, Embase, and Cochrane databases were searched through December 2024. Twenty-two trials (n=1,908 patients; Fitzpatrick skin types II–V) met inclusion criteria. Primary outcome was change in Modified Melasma Area and Severity Index (mMASI). Secondary outcomes included recurrence at 6 months, post-inflammatory hyperpigmentation (PIH), and patient-reported satisfaction. Random-effects models were used with heterogeneity assessed by I². Results: Pooled mMASI reduction was 46.2% (95% CI 41.8–50.6) at end of treatment across all wavelengths, with 1064 nm demonstrating superior performance in Fitzpatrick IV–V skin (52.1% vs 39.4%; p<0.01). Recurrence at 6 months occurred in 34.7% of patients, most commonly within 8–16 weeks of last treatment. PIH incidence was 6.3%, significantly lower than historical nanosecond controls (17–22%). Combination with topical tyrosinase inhibitors improved durability of response. Conclusions: Picosecond laser therapy produces meaningful mMASI improvement with a favorable safety profile across skin types, though recurrence remains common and adjunctive topical maintenance is recommended.