Melasma treatment utilizes multiple laser modalities. However, the effectiveness of picosecond laser in treating melasma remains unclear. The present study investigated the efficacy and safety of a picosecond laser for melasma treatment. 

It searched for randomized controlled trials (RCTs) that compared picosecond laser with conventional treatment for melasma through five databases. The study used the Melasma Area Severity Index (MASI)/modified MASI (mMASI) to quantify the degree of melasma improvement. 

The study observed:

• Inclusion of six RCTs, which employed picosecond laser at 1064, 755, 595 and 532 nm wavelengths.
• Significant reduction in the MASI/mMASI, but highly heterogeneous results, with picosecond laser.
• Significant reduction in the MASI/mMASI with no significant side effects by 1064 nm picosecond laser compared with 755 nm picosecond lasers.
• No significant improvement in the MASI/mMASI by 755 nm picosecond laser compared with topical hypopigmentation agents and the appearance of post-inflammatory hyperpigmentation.
• An insufficient sample size restricted the use of other laser wavelengths in the subgroup analysis. 

This study shows that a picosecond laser at 1064 nm is safe and effective in treating melasma. However, a picosecond laser at 755 nm cannot be deemed superior to topical hypopigmentation agents in treating melasma. Furthermore, large-scale RCTs should verify the precise efficacy of other wavelengths of picosecond laser for melasma treatment.

Source: Feng J, Shen S, Song X, Xiang W. Efficacy and safety of picosecond laser for the treatment of melasma: a systematic review and meta-analysis. Lasers Med Sci. 2023;38(1):84.