Treatment Outcomes in Birdshot Chorioretinitis: Corticosteroid Sparing, Corticosteroid Discontinuation, Remission, and Relapse

Abstract

To describe treatment-related outcomes among patients with birdshot chorioretinitis (BSCR). Retrospective cohort study. Patients diagnosed with BSCR at 2 tertiary care academic medical centers. Clinical and treatment-related data were collected for all patients with BSCR diagnosed between 2003 and 2017 at the 2 centers and for each eye at each clinical visit. Four outcomes were considered: (1) corticosteroid-sparing success, defined as inactive disease and prednisone dose of ≤7.5 mg/day; (2) corticosteroid-discontinuation success, defined as inactive disease and discontinuation of prednisone; (3) sustained drug-free remission, defined as inactive disease off all medications for ≥3 months; and (4) relapse of BSCR after remission. A total of 107 patients with BSCR were identified, of whom 94 had follow-up data. Corticosteroid-sparing success was achieved in 95.4% of the oral corticosteroid-treated patients at a rate of 0.60 successes per person-year (PY) (95% CI: 0.50/PY, 0.70/PY). The median time to corticosteroid-sparing success was 12 months. Corticosteroids were discontinued successfully in 76.5% of oral corticosteroid-treated patients (rate= 0.28/PY; 95% CI: 0.21/PY, 0.35/PY). The median time to successful corticosteroid discontinuation was 2.0 years. A sustained drug-free remission was achieved in 24 patients (rate= 0.06/PY; 95% CI: 0.04/PY, 0.09/PY), with approximately 25% of patients achieving remission by 4 years of follow-up. Relapse of inflammation in patients after achieving a sustained, drug-free remission occurred at a rate of 0.24/PY (95% CI: 0.14/PY, 0.37/PY). Successful corticosteroid sparing and discontinuation was achieved in the majority of patients with BSCR. Remission occurred less often, but data were limited by the time needed to induce a remission (4 years) and the amount of follow-up (median, 4.6 years). The relapse rate after a remission was 0.24/PY.