Bilateral retrobulbar optic nerve infarctions after blood loss and hypotension. A clinicopathologic case study.

A 59-year-old woman with anemia became totally blind after repeated gastrointestinal bleeding and acute hypotension. Neuropathologic examination was normal apart from bilateral infarctions centered on the orbital portion of the optic nerves. This is the only "pure" histopathologic study of visual loss after hemorrhage and hypotension in the recent literature, the single previous case being complicated by arteriosclerosis and vasculitis. The authors suggest that visual loss after hypotension is of three types. Profound hypotension in patients with neither anemia nor arteriosclerosis generally causes water-shed infarctions in the parietal and occipital lobes. Brief hypotension combined with arteriosclerosis favors juxtalaminar optic nerve infarction indistinguishable from spontaneous anterior ischemic optic neuropathy. In anemic patients without arteriosclerotic risk factors, hypotension is likely to cause infarction in the orbital optic nerve, where pial end vessels are subject to compression from hypoxic edema.