Ophthalmological Abnormalities in Cases with Intracranial Aneurysms: A Retrospective Referral-Based Study.

Background: Intracranial aneurysms affect 2-3% of the population. Ophthalmological symptoms, such as ophthalmoplegia and visual field defects, can be symptoms of unruptured intracranial aneurysms. In this study, we reported the frequency of ophthalmological abnormalities and the relationship between these abnormalities and treatment and life prognosis. Methods: One hundred forty-two patients who were referred from the Kyoto University Hospital Neurosurgery Department to the Ophthalmology Department between January 2011 and October 2022 were enrolled in this study. Age, sex, aneurysm location, visual field defects, ophthalmoplegia, presence of subarachnoid hemorrhage, treatment, and death during follow-up were retrospectively investigated. Results: Of the 142 patients, internal carotid artery aneurysms were the most frequent (93 cases), followed by internal carotid-posterior communicating artery (IC-PC) aneurysms (20 cases). Cranial nerve III palsy was observed in 50% of cases with IC-PC aneurysms, and this frequency was higher compared to cases with other aneurysms (p=0.0095). Post-chiasmal visual field defects were present not only in patients with anterior circulation aneurysms (anterior communicating artery, 25%; internal carotid artery, 19%; and middle cerebral artery, 33%), but also in patients with posterior circulation aneurysms (basilar artery, 21%). Conclusions: Cranial aneurysm not only causes III palsies but also causes visual field defects. Our findings support careful ophthalmologic assessment, including visual field testing when clinically feasible, especially when aneurysms are large or near the visual pathway, regardless of the anatomical position of the originating artery.