Abstract: Objective To estimate the efficacy and safety of Interferon （INF）α2a as an add-on treatment for refractory Behcet’s uveitis(BU). Design Retrospective case series. Participants 36 patients (70 eyes) with refractory BU who underwent relapse under corticosteroids and conventional immunosuppressive agents in Beijing Tongren Eye Center from November 2016 to December 2019 were included. Methods The outpatient medical records were reviewed. All patients took INFα2a as an add-on treatment. Linear regression, Logistic regression and Chi-square test were used to reveal the correlation between the change of frequency of relapse, vision, dosage of corticosteroids, dosage of immunosuppressive agents and gender, age, course of BU, immunosuppressive agents, baseline vision, follow- up duration. The side effects were monitored. Main Outcome Measures  Changes in ocular relapse frequency and vision acuity, changes of the dosage of corticosteroids and immunosuppressive agents, and side effects. Results During a mean follow-up of 16.6±7.4 (12~36) months, the median frequency of relapse decreased from 7.5 (range 4~12) per year to 0 (range 0~2) per year (P=0.000). Linear regression revealed no correlation between the decreased frequency of relapse and gender, age, course of BU, immunosuppressive agent, baseline vision, follow-up duration (P>0.05). Visual improvement was observed in 25 eyes (35.7%) ,visual stability was observed in 24 eyes (34.3%), and visual deterioration was observed in 21 eyes (30%). Corticosteroids were lowered in 31 patients (86.1%), the dosage were reduced to lower than 10mg/day in 12 patients (32.9%) , and completely withdrawn in 2 patients (2.9%). Immunosuppressive agents were reduced in 20 patients (55.6%). Logistic regression revealed no correlation between the change of vision, dosage of corticosteroids, dosage of immunosuppressive agents and gender, age, course of BU, immunosuppressive agent, baseline vision, follow-upduration (P>0.05). No severe adverse events were observed. Conclusion INFα2a is effective and safe for refractory BU as an add-on treatment. (Ophthalmol CHN, 2020, 29: 273-277)

Key words: interferon α2a, Behcet’s uveitis