Microanatomy of the blood supply to the optic nerve.

The vascularization to the optic nerve is understood to come from the superior hypophyseal arteries and ophthalmic artery. However, anatomical studies about their detailed distribution to the optic nerve, especially its intracanalicular part, are rare. As the optic nerve is very prone to compression inside the optic canal, the vascularization here is especially at risk. This study shows that the superior hypophyseal arteries are the main source of blood supply to the intracranial and intracanalicular part of the optic nerve. The contribution of the ophthalmic artery to this part of the nerve is negligible. This artery mainly contributes to the intraorbital part of the optic nerve by means of the short and long ciliary arteries and the central retinal artery.