Oculomotor disturbance is the common manifestation of intracavernous carotid aneurysm cases. Intracavernous carotid aneurysms causing compressive optic neuropathy with no oculomotor disturbance are relatively rare due to their anatomical characteristics. We experienced a case of intracavernous carotid aneurysm which resulted in a shifted supraclinoid segment of the internal carotid artery, presenting with visual loss and visual field defect with no oculomotor disturbance.

A 40-year-old woman presented with loss of vision in the right eye. A relative afferent pupillary defect was observed in this eye. Visual field test showed quadranopsia in the right eye. Magnetic resonance imaging revealed that the intracavernous carotid aneurysm had shifted the supraclinoid segment of the internal carotid artery to the superomedial position. The right optic nerve was directly molded by the shifted supraclinoid segment of the internal carotid artery at the point of the bifurcation between the anterior cerebral artery and the middle cerebral artery. A Guglielmi detachable coil (GDC) embolization was performed successfully with no operational complications. Six months after coiling, best corrected visual acuity of the right eye was 1.0, and the visual field defect had recovered in all except the superior temporal field.

Oculomotor disturbance is frequently associated with intracavernous carotid aneurysms. Nevertheless, optic neuropathy without oculomotor disturbance may be the only sign in patients with an intracavernous carotid aneurysm that causes shifting of the supraclinoid segment of the internal carotid artery.