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 the
superficial pial plexus and direct intraneural branches. The aim of the study
was to study the morphological characteristics (origin, number of arteries,
calibers, and branching pattern) of perioptic arterial vascularization and
intraoptic 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 in
the structures of the nervous system. The vasculature of the optic nerves
was microdissected and examined under the stereoscopic microscope, after
injecting their arteries with 10% mixture of India ink and gelatin, and
5% formaline fixation.
Results. The intracanalicular part of the optic nerve received fine blood
vessels 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 the
nerve. The intraorbital segment of the optic nerve was supplied by two
interconnected systems of blood vessels, peripheral and axial, both coming
from the central retinal artery.
Conclusion. On the basis of the obtained results, it has been confirmed
that both segments of the optic nerve have a rich and very delicate vascular
network. The superficial pial arterial plexus of the intracanalicular segment
of the optic nerve has been identified as the only source of its vascular
supply. The intraorbital part of the optic nerve has two interconnected
systems of blood vessels: peripheral and axial.