Acute Vision Loss Following Intravitreal Ganciclovir Injection in Cytomegalovirus Retinitis: A Case Report

Purpose: We present a rare case of acute visual acuity loss following intravitreal ganciclovir injection for the treatment of cytomegalovirus (CMV) retinitis.Case summary: A 35-year-old woman receiving immunosuppressive therapy for systemic lupus erythematosus developed CMV retinitis in the left eye. Oral valganciclovir was initiated but discontinued due to cytopenia and treatment was switched to intravitreal ganciclovir injections (2 mg/0.04 mL). One year later, CMV retinitis developed in the right eye and the same regimen was initiated. Although receiving bilateral injections at two-week intervals, the patient experienced a sudden decrease in visual acuity in the right eye one day after injection, 10 months after treatment initiation. Optical coherence tomography and fluorescein angiography revealed inner retinal edema and focal macular leakage. Treatment was switched to intravenous foscarnet resulting in resolution of macular edema; however, central retinal thinning persisted. Owing to recurrent retinitis, intravitreal ganciclovir injections are currently being continued at a reduced dose (1 mg/0.02 mL).Conclusions: Acute visual acuity loss may rarely occur following intravitreal ganciclovir injection in patients with CMV retinitis. Careful consideration of potential mechanical injury and drug-induced retinal toxicity is needed during treatment.