A Retrospective Study of Q-Switched Alexandrite Laser in Treating Nevus of Ota

BACKGROUND The Q-switched alexandrite laser (QSAL) has been clinically proven to be effective in treating nevus of Ota, but a large-scale retrospective study with long-term follow-up has never been performed. OBJECTIVE To evaluate the efficacy of the QSAL in treating nevus of Ota, the laser's long-term side effects, complications associated with the treatments, and the recurrence rate. MATERIALS AND METHODS Eight hundred six patients (651 female, 155 male) with a diagnosis of nevus of Ota who had received a series of QSAL (wavelength 755 nm) treatments were recruited. The typical settings were fluences of 3.8 to 4.8 J/cm2 and a spot size of 3 mm. Follow-ups were conducted via questionnaire with 590 patients who had completed the treatment at least 3 years earlier. RESULTS Overall, 93.9% of patients achieved complete clearance after an average of 5.2 sessions. All recurrences (0.8%) appeared beyond the previously treated sites. No long-term adverse effects, including hypopigmentation, hyperpigmentation, textural changes, and malignant transformation, were observed. CONCLUSION The QSAL is a safe and effective modality for treating nevus of Ota. Recurrence was rare and appeared beyond the previously treated sites. The authors have indicated no significant interest with commercial supporters.