Prognostic Factors of Treatment Failure with First-Line Corticosteroid-Sparing Agents in Patients with Birdshot Chorioretinopathy: A Retrospective Study.

Purpose: To investigate prognostic factors of treatment failure with first-line corticosteroid-sparing agents in patients with birdshot chorioretinopathy (BCR).

Methods: This retrospective single center study recruited patients with HLA A29-positive BCR between 2004 and 2023. First-line treatment consisted in oral corticosteroids (prednisone) and mycophenolate mofetil (MMF) or interferon alpha-2a (IFN). Second-line treatment consisted in biologics, i.e. anti-TNFα or tocilizumab (TCZ). At baseline, the characteristics of patients treated with MMF/IFN and patients requiring biologics were compared.

Results: Forty-three patients (86 eyes) were included. Mean follow-up duration was 7.9 +/- 5.6 years. All patients were treated with prednisone. MMF/IFN was successful in 22 patients, while 21 patients required biologics. At baseline, clinical papillitis and angiographic leakage of the optical nerve were statistically more frequent in patients requiring biologics compared to patients treated with MMF/IFN, p = 0.004 and p = 0.003 respectively. At baseline, retinal nerve fiber layer (RNFL) thickness was elevated in patients requiring biologics (153 vs 117 μm; p = 0.02). At baseline, mean deviation evaluated by automatized visual field was significantly worse in patients requiring biologics (-7.85 vs - 4.87 ; p = 0.04). Among 11 patients treated sequentially with MMF, anti-TNFα and TCZ, mean prednisone dose significantly decreased with anti-TNFα compared to MMF (13.2 vs 21.9 mg/day, p = 0.002), TCZ compared to MMF (5.7 vs 21.9, p < 0.001) and TCZ compared to anti-TNFα (5.7 vs 13.2, p = 0.001).

Conclusion: At baseline, clinical papillitis, angiographic papillary leakage, RNFL thickness and mean deviation could be prognostic factors of treatment failure with first-line corticosteroid-sparing agents in patients with BCR.