An unusual cause for an optic disc haemorrhage.

A 51-year-old male on chemotherapy for myeloma presented initially with a unilateral optic disc haemorrhage and signs of optic neuropathy. This rapidly progressed to affect both eyes and within a few days he developed retinal features suggestive of progressive outer retinal necrosis. He was treated with intravenous acyclovir that was subsequently changed to ganciclovir when serological tests for cytomegalovirus were found to be positive for immunoglobulin M antibodies. His visual loss continued to deteriorate despite treatment, and he subsequently developed a retinal detachment in one eye. The causes of optic neuropathy in immunocompromised patients and the importance of eliminating an infective cause are discussed.