Abstract: Objective To observe the efficacy and safety of intense pulsed light （IPL） incorporated with optimal pulse technology （OPT） in the treatment of patients with solar lentigines. Methods A total of 173 patients were treated with IPL-OPT for four sessions at an interval of 3 weeks. Among them, 113 patients presented with small plaques of lentigines （1 cm or shorter in diameter）, 21 patients with large plaques （more than 1 cm in diameter）, and 39 patients with mixed plaques. Treatment results were evaluated and rated by physicians three weeks after each session based on improvement in pigmentation and area of lesions on photograph. In addition, subjective satisfaction was assessed in physicians and patients, according to a four-grade scale. Results After the fourth session, 92.49% （n = 160） of patients experienced more than 50% improvement and 42.77% （n = 74） more than 75% improvement. An improvement of more 50% was achieved in 94.69% （n = 107） of patients with small plaques, 85.71% （n = 18） of patients with large plaques, and 89.74% （n = 35） of patients with mixed plaques with no significant difference among them. Over 50% of patients with small plaques showed more than 70% improvement. The satisfaction rates of physicians and patients were 95.38% （165/173） and 91.91% （159/173）, respectively, showing no statistical difference (χ2 = 1.75, P > 0.05). Conclusion IPL-OPT is a non-ablative, safe and effective treatment for solar lentigines, with relatively few side effects.

Key words: Optimal pulse technology, Intense pulsed light, Solar lentigines