Delayed-onset cytomegalovirus retinitis after 0.2 µg/day fluocinolone acetonide implantation: a case series

PURPOSE: To describe the clinical features and outcomes of cytomegalovirus retinitis (CMVR) presenting after intravitreal fluocinolone acetonide (FAc) implantation. METHODS: Single centre, retrospective observational case series involving three patients who developed CMVR several months after FAc implantation at the uveitis department at Moorfields Eye Hospital, London, UK. Clinical history, immune status, ocular findings, imaging, and management were reviewed. RESULTS: The first patient with pulmonary sarcoidosis and no systemic treatment presented 14 months post-implant with granular retinitis and severe occlusive retinal vasculitis. He developed renal toxicity to valganciclovir, necessitating intravitreal foscarnet and FAc implant removal. The second patient with presumed ocular sarcoidosis on multiple immunosuppressive agents developed fulminant necrotising CMVR eight months after FAc implantation and responded well to systemic valganciclovir with adjunctive intravitreal foscarnet therapy. The third patient, an elderly man with previous CMV retinitis in the context of follicular lymphoma, experienced reactivation at the margin of an old scar several months after FAc implantation and was stabilised with intravenous and intravitreal foscarnet. Although two patients had bilateral implants, the retinitis remained unilateral. Across cases, presentations ranged from granular retinitis with vasculitis to fulminant necrosis and late reactivation. CONCLUSION: Delayed-onset CMVR can occur in eyes treated with FAc implants, particularly in immunosuppressed patients. Recognition of atypical presentations, early PCR testing and timely antiviral therapy are essential to preserve vision.