Angioarchitecture of intracanalicular part of monkey optic nerve.

The angioarchitecture of the monkey intracanalicular optic nerve was examined, after injecting silicone rubber into the ophthalmic artery. Particular attention was focused on the possible existence of the end artery which might play an important role in posterior ischemic optic neuropathy or indirect injury to the intracanalicullar part of the optic nerve. In the intracanalicular optic nerve, the vascular architecture consisted of branches from the ophthalmic artery. Some branches derived from the chiasmal part of the ophthalmic artery, some from its intracanalicular part, and others from its intraorbital part. On the surface of the intracanalicular optic nerve and in its inner portion, vascular distribution was sparse. A clear pial plexus was not observed. However, it was ascertained that there existed a few anastomoses between the branches from the ophthalmic artery on the surface of the optic nerve, and between the intraneural branches within the optic nerve: no end artery appeared to exist.