Ischemic optic neuropathy associated with subarachnoid hemorrhage after rupture of anterior communicating artery aneurysm.

Two clinical cases in which ischemic optic neuropathy (ION) occurred after subarachnoid hemorrhage (SAH) are reported. Hemorrhage in the proximity of the optic chiasm was confirmed in 2 cases following rupture of an anterior communicating artery aneurysm. Optic disk atrophy with excavation and permanent visual field defect (altitudinal superior hemianopia) occurred in both cases. ION seems to occur in association with the optic nerve coincidental with the hyperdensity side of SAH on head CT scan. The incidence of ION appears to be attributable to an insufficient blood supply to arteries distributed in the posterior part of the optic nerve as a result of SAH.