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. Infographic on melasma study with assessments, treatment and key findings for 100 women.The infographic presents a study on 100 women with facial melasma, divided into two subtypes: M (pigmentary melasma, n=50) and M+V (pigmentary-vascular melasma, n=50). Treatment involved a fractional-mode 694 nm Q-switched ruby laser over 3 sessions every 4 weeks, with assessments at week 12. Assessments included Clinical: MASI, VISIA: brown spots, ultraviolet spots, red areas, Dermoscopy: vascular quantity/morphology and patient-reported improvement and satisfaction. Key findings: Week 12 MASI reduction was 71.1 percent ± 13.5 percent for M and 51.2 percent ± 12.3 percent for M+V. ≥ 50 percent MASI improvement was 95.2 percent for M and 56.3 percent for M+V. Greater reduction in VISIA brown and ultraviolet spots in M. Red areas decreased in both subtypes; between-subtype longitudinal difference not significant. M subtype independently predicted greater week 12 MASI improvement. Treatment was generally well tolerated in both subtypes.