Subtype-Specific Response to Fractional-Mode Q-Switched Ruby Laser in Melasma: A Prospective Single-Blind Clinical Study Using Clinical and Noninvasive Imaging Assessments.

OBJECTIVE

Melasma is a chronic relapsing facial hyperpigmentation disorder with pigmentary and vascular heterogeneity. This study compared responses of pigmentary melasma (M), characterized predominantly by brown hyperpigmented macules or patches with non-dominant vascularity, and pigmentary-vascular melasma (M+V), characterized by pigmentation with persistent erythema or telangiectatic vascular features, to fractional-mode 694 nm Q-switched ruby laser.

METHODS

In this prospective, single-center, single-blind clinical study with assessor-blinded outcome evaluation, 100 women with facial melasma were classified at baseline as M (n = 50) or M+V (n = 50) by clinical examination and dermoscopy. All received three laser sessions at 4-week intervals. Outcomes included MASI, VISIA brown spots, ultraviolet spots, red areas, dermoscopic vascular scores, responder status, patient-reported improvement, satisfaction, and adverse events.

RESULTS

Ninety patients completed week 12 assessment (M, n = 42; M+V, n = 48). Week 12 MASI percentage reduction was 71.1% ± 13.5% in M versus 51.2% ± 12.3% in M+V (P < 0.001), and ≥50% MASI improvement occurred in 95.2% versus 56.3% of patients, respectively (P < 0.001). M showed larger reductions in VISIA brown and ultraviolet spots. Red-area scores decreased in both groups, but between-subtype longitudinal reduction was not significant. MASI improvement correlated with VISIA brown (r = 0.502) and ultraviolet spots (r = 0.390), but not red areas. In multivariable analysis, M subtype independently predicted greater week 12 MASI improvement. Treatment was generally well tolerated.

CONCLUSION

Fractional-mode 694 nm Q-switched ruby laser improved both subtypes, but pigmentary melasma showed a more favorable response. Baseline clinicodermoscopic subtype classification and multimodal assessment may support individualized laser treatment and response evaluation.