Unruptured aneurysms can compress the third cranial nerve and the anterior visual pathways.
Ruptured aneurysms and subarachnoid hemorrhage can result in Terson syndrome and papilledema. Direct and indirect carotid-cavernous fistulas most commonly cause the classic traid of proptosis, conjunctival chemosis, and cranial bruit but can masquerade as chronic conjunctivitis. Arteriovenous malformations, with or without hemorrhage, may compress portions of the retrochiasmal pathways, causing visual field loss. Cavernous malformations, when in the brainstem, commonly cause abnormalities of supranuclear, nuclear, and fascicular ocular motility. The ophthalmologist may be the first physician to encounter clinical manifestations of intracranial vascular abnormalities that may herald devastating neurologic complications.