Large Aneurysm of the Internal Carotid Artery Presenting as Bitemporal Hemianopia

A 63-year-old woman presented at our clinic with an inability to see out of both eyes, which had originated 6 months earlier. The gradual loss of vision was painless. Neuro-ophthalmic examination revealed 0.5/0.5 vision. Bitemporal hemianopia was detected by perimetry. Brain magnetic resonance imag-ing revealed a well-defined mass in the sellar and suprasellar areas (Figure 1A). There was no subarachnoid hemorrhage. A cerebral angiogram con fi rmed a right internal carotid aneurysm, measuring 1.8 cm anterior-posteriorly, 2.2 cm transversely, 1.9 cm craniocaudally, and projecting posteromedially (Figure 1B). Given the long history, we thought that her prognosis for visual recovery would be poor and that the risks of surgical intervention outweighed the potential bene fi ts at this time. Instead, coil embolization was planned. Although successful coil embolization was performed, the bitemporal hemianopia did not recover after the intervention, suggesting that the damage to the optic chiasm was irreversible or that our intervention did not eliminate the cause of compression.