Adenoviral Retinitis: A Rare Case Presentation of a Common Virus

To report a rare case of bilateral necrotising retinitis caused by a potentially novel human adenovirus D (HAdV-D) in a post-bone marrow transplant patient and to highlight the diagnostic challenges and therapeutic role of intravenous cidofovir, alongside a review of previously reported cases of human adenovirus (HAdV) retinitis. Retrospective case report. A 60-year-old man with a history of acute myeloid leukaemia, in remission post-bone marrow transplant, presented with bilateral hypertensive granulomatous panuveitis and necrotising retinitis. Repeated aqueous polymerase chain reaction (PCR) testing for herpes simplex virus, varicella-zoster virus, cytomegalovirus, syphilis and Toxoplasma gondii was negative and the patient showed a poor response to multiple empirical antiviral therapies. This led to expanded PCR testing which detected high HAdV loads in both aqueous and vitreous samples. Genomic sequencing confirmed the presence of a potentially novel HAdV-D. The patient received intravenous cidofovir with close renal monitoring. Serial aqueous PCR demonstrated a substantial reduction in HAdV load, with corresponding clinical improvement and complete resolution of active retinitis, replaced by retinal scarring. Final best-corrected visual acuities were 0.4 LogMAR in the right eye and hand movements in the left eye. HAdV retinitis, though rare, should be considered in immunocompromised patients with progressive necrotising retinitis that is unresponsive to conventional antivirals, particularly when associated with repeatedly negative PCR for herpes viruses, syphilis and Toxoplasma gondii. Intravenous cidofovir may be an effective off-label treatment. A multidisciplinary approach is essential, and serial aqueous PCR is useful for monitoring treatment response.