Abstract: 【Abstract】 Objective To compare the efficacy and safety of broad-band intense pulsed light （OPT-IPL） versus narrow-band intense pulsed light （DPL） in the treatment of rosacea-associated erythema and telangiectasia. Methods Fifty-four rosacea patients who received treatment with intense pulsed light were collected from Laser Department, Hospital of Dermatology, Chinese Academy of Medical Sciences from October 2016 to December 2019, and clinical data were retrospectively analyzed. Their age ranged from 19 to 56 years, and disease duration ranged from 0.2 to 10 years. Of the 54 patients, 22 were treated with OPT-IPL, and 32 were treated with DPL. All patients completed at least one session of treatment and follow-up. Therapeutic efficacy was evaluated by using clinician erythema assessment（CEA）and physician global assessment（PGA）scales, and adverse reactions were assessed. A generalized linear mixed model was used to analyze differences in CEA and PGA scores among different groups and treatment sessions. Results In the OPT-IPL group, 22, 17 and 10 cases completed 1, 2 and 3 sessions of treatment respectively, with the energy fluence being 16.57 ± 1.21 J/cm2. In the DPL group, 32, 25 and 16 cases completed 1, 2 and 3 sessions of the treatment respectively, with the energy fluence of 9.76 ± 0.61 J/cm2. Before the start of treatment and after 1, 2 and 3 sessions of treatment, the CEA scores were 2.38 ± 0.84, 2.29 ± 0.75, 1.94 ± 0.66 and 1.90 ± 0.66 respectively in the OPT-IPL group, and 2.25 ± 0.77, 2.16 ± 0.77, 1.84 ± 0.81 and 1.47 ± 0.81 respectively in the DPL group. As far as the CEA score was concerned, there was no interaction between the groups and treatment sessions （F = 0.57, P = 0.638）, and no significant difference between the OPT-IPL group and DPL group （F = 0.84, P = 0.360）, but a significant difference was observed among different sessions of treatment （F = 17.90, P < 0.001）, and the CEA score gradually decreased along with the increase of treatment sessions compared with that before treatment （all P < 0.05）. After 1, 2 and 3 sessions of treatment, the PGA scores were 0.39 ± 0.71, 0.82 ± 0.92 and 0.55 ± 0.80 respectively in the OPT-IPL group, and 0.61 ± 0.77, 1.34 ± 1.09 and 1.53 ± 1.38 respectively in the DPL group. As far as the PGA score was concerned, there was no interaction between the groups and treatment sessions （F = 1.62, P = 0.202）, and no significant difference between the OPT-IPL group and DPL group （F = 3.93, P = 0.050）, but there was a significant difference among different sessions of treatment （F = 19.33, P < 0.001）. Compared with the PGA score after 1 session of treatment, the PGA score gradually increased along with the increase of treatment sessions （all P < 0.001）. After treatment, no adverse reactions, such as blisters and crusts, occurred in either of the 2 groups, and there was no significant difference in the incidence of pigmentation, erythema aggravation, papules or increase in papule count between the 2 groups （all P > 0.05）. Conclusion The efficacy and safety of DPL are comparable to those of OPT-IPL in the treatment of rosacea-related erythema and telangiectasia, but lower energy fluence is required.

Key words: Rosacea, Erythema, Telangiectasis, Phototherapy, Intense pulsed light, OPT-IPL, DPL