THE ROLE OF AZATHIOPRINE IN THE MANAGEMENT OF RETINAL VASCULITIS

Purpose Azathioprine is commonly used as a second-line immunosuppressi ve agent in the management of patients with retinal vasculitis. The ai m of this study was to determine the efficacy of azathioprine by evalu ating its effect on relapse rate, clinical outcome and maintenance ste roid dose. Methods A retrospective analysis was performed of 34 patien ts presenting over 15 years to the Medical Eye Unit at St Thomas' Hosp ital. Relapse rate, steroid dosage, inflammatory score and visual acui ty were assessed before and during treatment with azathioprine. Result s Thirty-four patients (23 male) aged 17-70 years (median 41.4, median 38) were enrolled. Fifteen had idiopathic retinal vasculitis, 12 had Behcet's disease, 2 sarcoidosis, 2 sympathetic ophthalmia, 1 birdshot retinochoriodopathy, 1 Still's disease and 1 Harada's disease. The pri ncipal indications for azathioprine treatment were uncontrolled diseas e despite appropriate steroid therapy in 28 patients (82%) or to permi t a decrease in steroid dosage in 6 patients (18%). Frequency of relap se was assessed in 10 patients whose pre-treatment and treatment perio ds with azathioprine were of 1 year or greater. All were found to have a decreased replapse rate. In 60%, reduction of steroid dosage was ac hieved. Ocular inflammatory score decreased in 56% of eyes and visual acuity was improved or maintained in 64%. In 8 patients treatment had to be stopped due to side effects. Conclusion Within the limitations o f a retrospective study, we found azathioprine when used in combinatio n with systemic steroids to be most effective at reducing the relapse rate of retinal vasculitis, but only partially effective in allowing a reduction in steroid dosage.