Wilbrand's knee
Inferonasal fibres of the optic nerve which go into the contralateral optic nerve 4 mm before crossing over to the opposite optic tract. A lesion here produces a junctional scotoma.
Compression of the optic nerve near the chiasm may 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 1).
1)
Berson EL, Freeman MI, Gay AJ. Visual field defects in giant suprasellar
aneurysms of internal carotid. Report of three cases. Arch Ophthalmol. 1966
Jul;76(1):52-8. PubMed PMID: 5943676.