Intracranial vascular abnormalities.

Intracranial vascular abnormalities such as intracranial aneurysms, carotid-cavernous fistulas, AVMs, and cavernous malformations commonly produce neuro-ophthalmologic symptoms and signs. Unruptured aneurysms can compress the third cranial nerve and anterior visual pathways. Subarachnoid hemorrhage from ruptured aneurysms can result in Terson's syndrome and papilledema. Direct and indirect carotid-cavernous fistulas most commonly cause the classic triad of proptosis, conjunctival chemosis, and cranial bruit but can masquerade as chronic conjunctivitis. AVMs, 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. Prompt diagnosis facilitates appropriate management and therapy.