Internal Carotid Artery Aneurysm Presenting with Unilateral Nasal Hemianopsia

ABSTRACT

PURPOSE: To report a case of unilateral nasal hemianopsia caused by a large internal carotid artery aneurysm. CASE SUMMARY: A 56-year-old female presented with large cupping in the left optic nerve head detected incidentally during a routine check-up. She had no underlying systemic disease except hypertension. The best corrected visual acuity was 20/20 in both eyes and a slit-lamp examination showed no abnormal findings. Ophthalmoscopy showed cup/disc ratios of 0.6 in the right eye and 0.75 in the left eye. Relative afferent papillary defect or color vision defect was not observed. A Humphrey visual-field test indicated unilateral nasal hemianopsia in the left eye. Brain CT and angiography revealed a large 2.2-cm aneurysm on the left internal carotid artery. CONCLUSIONS: Internal carotid artery aneurysm should be considered as a possible cause of unilateral nasal hemianopsia in patients without intraocular lesion.