Intravitreal Corticosteroids in the Management of Refractory Macular Edema in Birdshot Chorioretinopathy.

Introduction: Birdshot chorioretinopathy (BCR) is a chronic, bilateral posterior uveitis characterized by yellow-white fundus lesions and a strong association with HLA-A29. Visual decline, often due to cystoid macular edema (CME) and retinal atrophy, necessitates early immunomodulatory therapy. This case report describes the clinical course of BCR and highlights the role of intravitreal corticosteroids in managing inflammation and CME.

Case report: A 54-year-old previously healthy male diagnosed with BCR based on clinical findings and a positive HLA-A29 test presented with refractory CME. Over 20 months, his best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were monitored. Initial treatment included topical corticosteroids, methotrexate, and oral corticosteroids to address anterior chamber reaction, vitritis, diffuse retinal lesions, and vasculitis. Cyclosporine was added for persistent inflammation but discontinued due to a cutaneous reaction. Despite these efforts, CME persisted, necessitating intravitreal corticosteroids. BCVA in the right eye (OD) fluctuated between 20/20 and 20/30, while the left eye (OS) ranged from 20/20 to 20/40, with changes linked to treatment adjustments. Recurrent CME episodes were more pronounced in the OS, where CFT varied from 328 to 637 µm, while OD values ranged from 304 to 576 µm. Intravitreal dexamethasone and fluocinolone implants reduced CFT in both eyes, achieving stabilization at the final assessment (OD 341 µm, OS 347 µm).

Conclusion: This case illustrates the challenges of managing BCR with refractory CME. While systemic immunomodulatory therapy is foundational, intravitreal corticosteroids play a vital role in controlling CME and preserving visual function. Combining systemic and local therapies proved essential for disease control. Long-term monitoring and individualized treatment are critical in managing this chronic condition.