[Aneurysm situated within the optic nerve].

A case of carotid-ophthalmic aneurysm of unusual location in the optic nerve is reported. The development of the disease was sudden: pain in the eye was followed by unilaternal blindness and manifestations of subarachnoid haemorrhage. The optic nerve was dilated balloon-like, cyanotic and vigorously pulsating. It was divided longitudinally and the aneurysmatic sac was exposed from the nerve. A vascular clip was put on its peduncle communicating with the cervico-ophthalmic portion of internal carotid artery. Despite preserved patency of the ophthalmic artery and partial continuity of the optic nerve, the vision of the eye didn't improve.