Visual field defect from ophthalmic artery aneurysm

A ipsilateral monocular superior nasal quadrantanopsia arrives when the ophthalmic artery aneurysm enlarges and impinges the lateral portion of the optic nerve (inferior temporal fiber compression).

If the ophthalmic artery aneurysm continues to enlarge then an upward displacement of the optic nerve against the falciform ligament produce a monocular inferior nasal quadrantanopsia by superior temporal fiber compression.

Compression of the optic nerve near the chiasm may also produce a superior temporal quadrant defect in the contralateral eye (junctional scotoma “pie in the sky” defect) from injury to the anterior Wilbrand's knee.