The purpose of this case report was to present a case of cytomegalovirus (CMV) retinitis in a patient with diffuse large B-cell lymphoma (DLBCL) post-CD19 chimeric antigen receptor (CAR) T-cell therapy. A 43-year-old female patient who was complaining of metamorphopsia and sudden blurring in the vision of her left eye was referred to the ophthalmology department. This evidence concerns the gene CD19 and retinitis.