orbital nerves and vessels

Orbital Vessels and Nerve

Raed Behbehani , MD FRCSC

Sensory Nerves

•V1 mostly.

•V2 few branches.

Sensory Nerves

Sensory Nerves

Sensory Nerve* Frontal nerve --> medial canthus,

upper lid, eyebrow.

* Branches of frontal nerve : Supra-orbital,

supratrochlear nv.*Lacrimal nv--> parasympathetic fibers to lacrimal

gland.

Sensory Nerves*The Nasociliary nerve--> long posterior ciliary nerve (globe) , senosry fibers through ciliary ganglion, and nasal mucosa,

skin at tip of nose.(Hutchinson’s

Sign)

Ciliary Ganglion• 1.5 mm Lateral to

the apical optic nerve.

• Sensory branches from nasociliary nerve.(pass through only).

• Parsympathetic fibers from (ciliary body and sphincter pupillae).(synapse)

• Sympathetic fibers from ICA for iris dilator muscle. (pass through only)

Ciliary Ganglion

Ciliary ganglion

Maxillary Nerve*V2 (maxillary)

nv. enters pterygopalatine ganglion through forman rotundum.*Infra-orbital nv.

main bulk continuation.* Sup. Alveloar--> gums,teeth, lateral upper

lip

Infra-orbital Nerve

• Main continuation of V2.

• Infra-orbital groove (surgical land mark)

• Provides sensation of lower lid,cheek, medial upper lip.

• * Zygomatic branch--> zygomaticomaxillary, and zygomaticfacial to innervate zygoma and lateral orbit.

Pterygopalatine Ganglion (PG)

* Parasympathetic ganglion of the head and neck.

* Greater Palatine nv. ->Palatine nerve-> PG-> Zygomaticotemporal-> Lacrimal nv.

Motor NervesOculomotor

•Exits brain stem between post-communicating and superior cerebellar artery.

•Lateral wall of cavernous sinus and divides into superior and inferior division.

•Through SOF through annulus of Zinn.

Oculomotor Nerve

Oculomotor Nerve

Oculomotor Nerve

Trochlear Nerve

Abducens Nerve

Nervus Intermedius

* Seperate cranial nv. closely

associated with CN VII.

* Int. Auditory Meatus--> geniculate

ganglion--> Greater Palatine nv.--> PG-

>Lacrimal gland

Arterial Supply

•The internal carotid artery give off the ophthalmic artery.

Ophthalmic Artery• Only ICA branch that

enters the orbit.

• Aastomoses with ECA branches.

• Enters orbit inferolateral to optic nerve.

• At orbital Apex Branches: to retina (CRA) and choroid (PCA).

• Short PCA : 15-20 from LPCA pierce sclera and supply ONH and choroid.

Muscular Branches

Branches of External Carotid

Artery* Orbital circulation has

high degree of collateralization with ECA .

* Supra-orbital and Supratrochlear<-->

Superficial temporal Art.* Dorsonasal <--> Angular

Art.*Ant and Post. Ethmoidal

<--> Sphenopalatine* Lacrimal Art. <--> Middle

Meningeal Art.

Venous Draiange

Venous Outflow•Valveless veins which drain

posteriorly.

•The Superior orbital vein (SOV) is a confluence of angular, naso-frontal, and Supra-orbital vein.

• Directed from medial to lateral.

•Starts near trochlea, medial to SR-->beneath SR--> Lateral to SR--> SOF.

Inferior Orbital Vein

•Drains posteriorly (anastomoses with Supra-orbital vein)--> Inferior orbital fissure--> into Pterygoid venous plexus and Inferior orbital fissure.

Superior Ophthalmic Vein

Cavernous Sinus

Orbital Vasculature•Ophthalmic artery (1st Branch of

ICA).

•Primary blood supply (small contribution from ECA: maxillary and

middle meningeal arteries).

•Branches variable.

•Ophthalmic artery enters the optic canal.

Branches of Ophthalmic Artery• Central retinal artery (Retina).

• Long posterior ciliary arteries (Choroid) ; 1)Short Posterior Ciliary Arteries (15-20) supply choroid and optic nerve head. 2) Long Post Cililary (2) for Iris and Ciliary body.

• Lacrimal artery. (gland) recurrent meningeal art. anastomosis

• Anterior & Posterior ethmoidal.

• Muscular Branches (divides into 2 long anterior ciliary arteries except LR has 1 only).--> anastom with long post. ciliary arteries (supply anterior segment).

Orbital Arterial Supply

Ophthalmic Artery

•Supraorbital artery (between levator and periorbita).

•Dorsal nasal.

•Supratrochlear.

Ophthalmic Art

Maxillary Artery

•Infra-orbital artery is the terminal end.

•Muscular branches to IR and IO.

•Anastomoses with angular artery and inferior palpebral vessels.

Orbital Arterial Supply

Venous Drainage of Orbit

Venous Drainage of Orbit

•Valveless superior and inferior ophthalmic veins.

•Confluence of the angular, supraorbital, and supratrochlear veins form superior ophthalmic vein.

• Inferior ophth vein receives tribuatries from muscular, vortex, and medial and lateral collateral veins.

• IOV communicates with pterygoid plexus via IOF.

SOV