Complete recovery from monocular blindness caused by aneurysmal compression to optic nerve--report of two cases.

Two patients with complete absence of light perception due to optic nerve compression were treated by decompressive procedures. Visual function progressively improved to the level of useful vision. A 42-year-old female with a partially thrombosed aneurysm in the right A1 of the anterior cerebral artery presented with right visual loss without light perception. The aneurysm was trapped and the intraluminal organized blood clot removed without dissecting the dome from the optic nerve. Her vision recovered to 20/20 1 week later. A 29-year-old male with a partially thrombosed saccular aneurysm of the anterior communicating artery presented with left monocular blindness. The aneurysm was clipped and the intraluminal clot removed without dissecting the aneurysmal wall from the optic nerve. His visual acuity gradually recovered to 10/20 12 days later. Visual recovery after decompressive procedures following prolonged absence of light perception due to optic nerve compression by aneurysms is rare. The pathophysiological mechanism of prompt visual recovery is unknown, but surgical treatment should be considered for any such patients.