Compressive Optic Neuropathy from the Normal and Abnormal Internal Carotid Artery

The internal carotid artery (ICA) is not traditionally thought of as a source of visual loss. Intracranial arterial dolichoectasia and saccular aneurysms from the ICA, as well as a normal-appearing ICA, can compress the optic nerve and cause compressive optic neuropathy. We describe 3 cases of patients with compressive optic neuropathy from an abnormal ICA and 1 case of a patient with a normal ICA, with concordant ophthalmologic findings.