Compressive Optic Neuropathy Caused by Internal Carotid Artery Aneurysm

Abstract

We report a case of a patient with compressive optic neuropathy caused by an internal carotid artery (ICA) aneurysm and treated with coil embolization. Case summary: A 54-year-old female patient complained of blurred vision of the left eye 1 week prior to her initial visit. Her best-corrected visual acuity was 8/20 in the left eye. Pupillary size was 3 and 4 mm in her right and left eyes, respectively. Relative afferent pupillary defect was detected in her left eye. Slit-lamp and fundus examination were normal. Visual field tests revealed an inferior visual field defect in her left eye. Brain magnetic resonance imaging showed a 9.5-mm-sized aneurysm compressing the optic chiasm of the distal ICA. She was diagnosed with compressive optic neuropathy due to an ICA aneurysm. Coil embolization was performed. Visual acuity and visual field defects had improved at the 2-month follow-up examination. Conclusions: An ICA aneurysm can compress the optic nerve and cause loss of vision. Early diagnosis and prompt treatment may prevent irreversible vision loss.