Background: Melasma is very difficult to treat, and often refractory to treatment. Various pigment-specific lasers have been used in melasma with unsatisfactory results. Fractional 694 nm Q-switched ruby laser, a novel modality for facial rejuvenation, is expected to be the treatment choice for melasma. Objectives: To evaluate the efficacy and safety of 694 nm fractional Q-Switched ruby laser in the treatment of melasma. Materials and Methods: Twenty females patients with clinical diagnosis of mixed and dermal type melasma were the subjects of this split face randomized control study. All patients were treated with 694 nm fractional Q ruby laser (4 mm spot size, 2.5-4 J/cm2 fluence) on one half of the face for 4 sessions with 4 weeks intervals. Pigmentation was objectively evaluated by using a colorimeter (lightness index), The subjective assessments were evaluated using the modified Melasma Area and Severity Index (mMASI) score. Patients’ self-evaluation of satisfaction and adverse events were also evaluated by using questionnaires. Results: Twenty-patients with skin phototype 3-4 were recruited into this study. The improvement rate of melasma on the laser sides after 1 and 3 months of the last treatment were about 2.54% and 1.18%, respectively. While the improvement rate of melasma on the control sides of the patients after 1 and 3 months of the last treatment were -4.06% and -1.48%, respectively. No statistical difference in the improvement rate of melasma was found between the control and laser groups (p-value ≥ 0.05). Evaluated by mMASI score, the laser sides show a decrease of mMASI from 16.5+8.1 to 14.6+6.5 and 15.2+6.5 at 1 and 3 months after the last treatment was completed but no statistically significant difference from the control sites (p-value = 0.736 and 0.812, respectively). The most common adverse effect was post-inflammatory hyperpigmentation; and, post-inflammatory hypopigmentation and urticaria were also found. Conclusion: The fractional 694 nm Q-Switched ruby laser was not an effective treatment method for melasma in Thai patients.
