Comparison of efficacy and safety of fractional 1064 nm picosecond laser and low-fluence Q-switched Nd:YAG laser in the treatment of melasma.

Melasma is a persistent and recurrent condition that remains difficult to manage effectively. Both fractional 1064 nm picosecond Nd:YAG (PSNY) and low-fluence Q-switched Nd:YAG (QSNY) lasers have been applied in treatment, yet there is currently insufficient data to compare their efficacy and safety. This retrospective study evaluated 99 female patients with melasma, including 54 treated with PSNY laser and 45 with QSNY laser. Each patient received two to five laser sessions at 2-4-week intervals. Clinical efficacy was evaluated by the modified Melasma Area and Severity Index (mMASI) at baseline, as well as four weeks following the second and fifth treatment sessions, with adverse events carefully documented. The PSNY laser produced a mean mMASI reduction of 23.7% and 40.7% after two and five sessions, respectively, while QSNY treatment achieved reductions of 9.8% and 29.5%. Although both modalities were safe and effective, PSNY laser demonstrated faster clinical improvement and required lower energy fluence. Post-inflammatory hyperpigmentation occurred in 7.4% of PSNY-treated patients and 13.3% of QSNY-treated patients, with no significant difference between groups. In conclusion, fractional PSNY laser therapy provides a rapid, safe, and effective alternative to QSNY laser for managing melasma.