Characteristics of perioptic and intraoptic arterial vascularization of extracranial segment of optic nerve

Abstract

Introduction. The optic nerve is supplied by the arterial branches of thesuperficial pial plexus and direct intraneural branches. The aim of the studywas to study the morphological characteristics (origin, number of arteries,calibers, and branching pattern) of perioptic arterial vascularization andintraoptic vascular network of the extracranial sections of the optic nerve:canalicular and intraorbital.Methods. The study included 18 pairs of the optic nerves of both sexes(11 males and 7 females), aged 51 to 78 years, with no signs of changes inthe structures of the nervous system. The vasculature of the optic nerveswas microdissected and examined under the stereoscopic microscope, afterinjecting their arteries with 10% mixture of India ink and gelatin, and5% formaline fixation.Results. The intracanalicular part of the optic nerve received fine bloodvessels from the ophthalmic artery, usually in two branches in 29 (82.9%)cases, while in 6 (17.1%) specimens there was only one branch for thenerve. The intraorbital segment of the optic nerve was supplied by twointerconnected systems of blood vessels, peripheral and axial, both comingfrom the central retinal artery.Conclusion. On the basis of the obtained results, it has been confirmedthat both segments of the optic nerve have a rich and very delicate vascularnetwork. The superficial pial arterial plexus of the intracanalicular segmentof the optic nerve has been identified as the only source of its vascularsupply. The intraorbital part of the optic nerve has two interconnectedsystems of blood vessels: peripheral and axial.