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Orbit and lacrimal apparatus
Moore clinical oriented anatomy
Gray’s anatomy for students
王淑慧
Orbit
Apex –optical canal
Base –bounded by orbital margin
Orbit –bony cavity lined with periosteum (periorbita)
Roof: orbital plate of frontal
bone, lesser wing of
sphenoid, lacrimal fossa
Medial: maxilla, lacrimal
bone, ethmoid, sphenoid
lacrimal groove
Lateral: orbital processes
of zygomatic , greater
wing of sphenoid
Floor: maxilla, orbital
processes of zygomatic
and palatine bones
Orbit communication‐ to face, scalp & nasal cavity
ant. & post. ethmoidal foramina ‐
ant & post ethmoidal n., a. & v.
Frontal bone
supraorbital notch or foramen‐
supraorbital n., a. and v., ophthalmic a. and v.
nasolacrimal duct
Zygomatic bone
zygomaticofacial foramen‐
zygomaticofacial n.
inf. orbital fissure‐
infraorbital and zygomatic n., a. and v.
Maxillary bone
infraorbital foramen‐
infraorbital n., a. and v. Orbit communication‐
from middle cranial fossa to orbit
optic canal optic nerve & ophthalmic artery
superior orbital
fissure
CN III, IV, V1, VI,
&ophthalmic veins
Orbits and placement of eyeballs within them
Ethmoidal cells, upper
nasal cavity and septum
Eyelids
• Cover eyeball : orbital part & palpebral part
• Protection : light & injury
• Moisture : spreading lacrimal fluid
• Moveable Eyelids
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Ext. : thin skin; cilia, ciliary gland
Orbicularis oculi m. levator palpebrae superioris m. Tarsal plate, tarsal gland : lipid, lubrication
Med. : palpebral conjunctiva
Conjunctival fornices (sac) ‟bursa
bulbar conjunctiva
Eyelids
Lat. Palpebral commissure
(Lateral canthi)
Med. Palpebral commissure
(medial canthi)
Med. palpebral lig. ( the origin and insertion of orbicularis oculi)
Lateral palpebral lig. (no muscle attachment)
Orbital septum : fibrous membrane & periosteum
Lacrimal apparatus
lacrimal
punctum
Nasopharynx
Innervation of lacrimal gland
Layers of eyeball
Fibrous layer: cornea, sclera
Vascular layer: choroid, ciliary body, iris, pupil
Inner layer: retina (optic & non‐visual parts)
Fibrous layer : cornea, sclera • post. 5/6
• “the white of the eye”
• Provide attachment •
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ant. 1/6
Sensitive to touch
CN V1 / ophthalmic N
Abrasions Lacrimal fluid & aqueous humor
(Corneoscleral junction)
capillaries loops Vascular layer: choroid, ciliary body, iris, pupil
•Dark brown layer
•The largest part
•Terminate in ciliary body
•Larger vessels near sclera
•Finest vessels near retina
Ciliary body
• ring‐like thickening of the layer posterior to the corneoscleral
junction, which is muscular & vascular
Ciliary muscle: control the thickness of the lens
Ciliary process: secrete aqueous humor, by zonular fibers (suspensory lig.) anchoring the lens
ciliary body
iris
Ciliary process
Iris
dilator pupillae, radially arranged;
sphincter pupillae, circularly arranged
Distribution of nerve fibers to ciliary ganglion and eyeball
Inner layer: optic & non‐visual parts retina
Retina
• Optic part
• Non‐visual part
 Ciliary part
 Iridial part
Refractive media of the eye
Cornea:
transparent, avascular, sensitive to touch; nourished by aqueous humor
Aqueous humor:
in ant. & post. chamber, produced by ciliary process, drained into scleral venous sinus
Refractive media of the eye
Cornea:
transparent, avascular, sensitive to touch; nourished by aqueous humor
Aqueous humor:
in ant. & post. chamber, produced by ciliary process, drained into scleral venous sinus
Refractive media of the eye
Cornea:
transparent, avascular, sensitive to touch; nourished by aqueous humor
Aqueous humor:
in ant. & post. chamber, produced by ciliary process, drained into scleral venous sinus
Lens: shaped by ciliary muscle
Vitreous humor: is a watery fluid enclosed in the meshes of the vitreous body
Fascial specializations
• Periorbita/ common tendinous ring
• Fascial sheath of the eyeball
• Check ligaments Periorbita
• common tendinous ring
Through common tendinous ring
Supporting apparatus of eyeball
Fascial sheath of the eyeball (Tenon’s capsule):
extending posteriorly from the conjunctival fornices to optic nerve, forming socket for eyeball; pierced by the tendons of the extra‐ocular muscle
Supporting apparatus of eyeball
• Medial check ligament : from the sheath of the medial rectus m. to lacrimal b.
• Lateral check ligament : from the sheath of the lateral rectus m. to zygomatic b.
• Suspensory ligament of the eyeball: the fascia of the inferior rectus m. and inferior oblique m.
Retrobulbar fat: resist the posterior pull on the eyeball produced by the rectus m.
Extra‐ocular muscles
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Sympathetic nerve ptosis
7= 4 rectus, 2 oblique, LPS
Sup. Tarsus & skin of the sup. eyelid
Extra‐ocular muscles
7= 4 rectus, 2 oblique, LPS
Origin: marginal bony (SO: sphenoid b., IO: ant. part of floor of orbit)
Insertion : eyeball (post. equator line of eyeball)
Extra‐ocular muscles
Origin: common tendinous ring Insertion : eyeball (sclera /post. to corneoscleral junction)
LPS
SR SO
MR
LR
origin
IR
7= 4 rectus, 2 oblique, LPS
Extra‐ocular muscles and their movements
elevation
Transverse axis
depression
Lateral rotate
Medial rotate
Innervation of orbit
Innervation of the orbit and eyeball
 Optic nerve (CNII)
 Oculomotor nerve (CN III)
 Trochlear nerve (CN IV)
 Abducens nerve (CN VI)
(Innervation of extrinsic eye muscles) Ophthalmic nerve (CNV1)
 Nasociliary nerve : long ciliary n., ant. & post. ethmoidal n
Infratrochlear n., communicating br. to ciliary
ganglion (Sensory root)
 Lacrimal nerve
 Frontal nerve : supraorbital & supratrochlear n
Optic Nerve
Innervation of the orbit and eyeball
 Optic nerve (CNII)
 Oculomotor nerve (CN III)
 Trochlear nerve (CN IV)
 Abducens nerve (CN VI)
(Innervation of extrinsic eye muscles) Ophthalmic nerve (CNV1)
 Nasociliary nerve : long ciliary n., ant. & post. ethmoidal n
Infratrochlear n., communicating br. to ciliary
ganglion (Sensory root)
 Lacrimal nerve
 Frontal nerve : supraorbital & supratrochlear n
Innervation of extrinsic eye muscles
LR6 SO4 AO3
Innervation of orbit
Innervation of the orbit and eyeball
 Optic nerve (CNII)
 Oculomotor nerve (CN III)
 Trochlear nerve (CN IV)
 Abducens nerve (CN VI)
(Innervation of extrinsic eye muscles)  Ophthalmic nerve (CNV1)
 Nasociliary nerve : long ciliary n., ant. & post. ethmoidal n.
Infratrochlear n., communicating br. to ciliary
ganglion (Sensory root)
 Lacrimal nerve
 Frontal nerve : supraorbital & supratrochlear n.
Innervation of orbit
Nerves of Orbit Distribution of V1 and V2 branches
ciliary ganglion Distribution of nerve fibers to ciliary ganglion and eyeball
Sup. Eyelid droop
Pupil dilated
Arteries of orbit
vessels of eyeball
Internal carotid a. → Ophthalmic a. →
Central retinal artery
supplies inner part of retina.
Long or short post. ciliary a → choroid
→ outer nonvascular layer of retina
ant. Ciliary a. → episcleral a.
Choroid v.→ vorticose v. →
posterior ciliary and ophthalmic veins.
Long post. & ant. Ciliary a. → ciliary plexus Vasculature of the ciliary body and iris
Ciliary plexus
Aqueous humor
Ciliary process
aqueous humor
scleral venous sinus
venous circulation
Glaucoma
Ophthalmic veins