Rapidly Sequential Vision Loss From Posterior Ischemic Optic Neuropathy Due to Methicillin-Susceptible Staphylococcus Aureus Bacteremia.

A 63-year-old man with a history of high-grade bladder cancer was admitted to the intensive care unit (ICU) with renal failure and methicillin-susceptible Staphylococcus aureus bacteremia originating from his nephrostomy tube. While in the ICU, he had painless, severe loss of vision in the right eye followed by his left eye 12 hours later. Visual acuity was no light perception in each eye. He was anemic, and before each eye lost vision, there was a significant decrease in blood pressure. Dilated fundus examination was normal, and MRI showed hyperintense signal in the bilateral intracanalicular optic nerves on diffusion-weighted imaging and a corresponding low signal on apparent diffusion coefficient imaging. He was diagnosed with bilateral posterior ischemic optic neuropathies (PION), and despite transfusion and improvement in his systemic health, his vision did not recover. PION may be seen in the context of sepsis, and patients with unilateral vision loss have a window for optimization of risk factors if a prompt diagnosis is made.