Chiasmatic groove

The superior surface of the body of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove, prechiasmatic sulcus), above and behind which lies the optic chiasma.

The groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity.