dr. sami zaqout faculty of medicine iugsite.iugaza.edu.ps/sizaqout/files/2012/02/the-orbital...2...

Dr. Sami Zaqout Faculty of Medicine IUG Dr. Sami Zaqout Faculty of Medicine IUG

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Orbital Region

1 Eyelids

Lacrimal Apparatus 2

3 The Orbit

The Eye 4

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Eyelids

• The eyelids protect the eye from injury and excessive light by their closure.

• The upper eyelid is larger and more mobile than the lower, and they meet each other at the medial and lateral angles.

• The palpebral fissure is the elliptical opening between the eyelids and is the entrance into the conjunctival sac.

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Eyelids Glands

• The ciliary glands (glands of Moll) are modified sweat glands that open separately between adjacent lashes.

• The sebaceous glands (glands of Zeis) open directly into the eyelash follicles.

• The tarsal glands are long, modified sebaceous glands that pour their oily secretion onto the margin of the lid; their openings lie behind the eyelashes.

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Eyelids - Medial Angle

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The Conjunctiva + Muscles

• The conjunctiva is a thin mucous membrane that lines the eyelids and is reflected at the superior and inferior fornices onto the anterior surface of the eyeball.

Subtarsal sulcus

foreign particles

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The Orbital Septum

• The framework of the eyelids is formed by a fibrous sheet.

• Attached to the periosteum at the orbital margins.

• Thickened at the margins of the lids to form the superior and inferior tarsal plates.

• Lateral palpebral ligament.

• The medial palpebral ligament.

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Lacrimal

Ducts

Lacrimal

Gland

Lacrimal

Apparatus


Lacrimal Gland

Large orbital

Small palpebral part

• The gland opens into the lateral part of the superior fornix of the conjunctiva by 12 ducts.

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Lacrimal Gland - Nerve Supply

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Lacrimal Ducts

Lacus lacrimalis

Puncta lacrimalis

Canaliculi lacrimales

Lacrimal sac

Nasolacrimal duct.

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The Orbit

• The orbit is a pyramidal cavity with its base in front and its apex behind.

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The orbital margin

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Orbital Walls

Roof Orbital plate of the

frontal bone

Lateral wall

Zygomatic bone

Greater wing of the sphenoid

Floor Orbital plate of the

maxilla

Medial wall

Frontal process of the maxilla

Lacrimal bone

Orbital plate of the ethmoid

Body of the sphenoid


Openings Into the Orbital

Cavity

Orbital opening one-sixth of the eye

Supraorbital notch supraorbital nerve and blood

vessels

Infraorbital groove and canal infraorbital nerve and blood

vessels

Nasolacrimal canal nasolacrimal duct

Inferior orbital fissure

maxillary nerve and its zygomatic branch

inferior ophthalmic vein

sympathetic nerves.

Superior orbital fissure

(Lacrimal, frontal, trochlear) nerves, superior ophthalmic vein

(Abducent, oculomotor, nasociliary) nerves

Optic canal

Optic nerve

Ophthalmic artery


Orbital Fascia

• The orbital fascia is the periosteum of the bones that form the walls of the orbit.

• It is loosely attached to the bones and is continuous through the foramina and fissures with the periosteum covering the outer surfaces of the bones.

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Ne

rve

s o

f th

e O

rbit

Optic Nerve Cerebrospinal fluid

Oculomotor Nerve

Superior ramus

Superior rectus m

Levator palpebrae superioris m

inferior ramus

Inferior rectus m

Medial rectus m

Inferior oblique m

Trochlear Nerve

Trigeminal Nerve

Ophthalmic division

Lacrimal Nerve

Frontal Nerve

Supratrochlear n

Supraorbital n

Nasociliary Nerve

Communicating branch

Long ciliary nn

Infratrochlear n

Posterior ethmoidal n

Anterior ethmoidal n

Maxillary division

Mandibular division Abducent Nerve

II

IV

III

V

VI


Oculomotor nerve [III]

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Trochlear nerve [IV]

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Ophthalmic nerve [V1]

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Ciliary Ganglion

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Internal Carotid Artery

Ophthalmic Artery

Central artery of the retina

Muscular branches

Ciliary arteries

Lacrimal artery

supratrochlear and supraorbital arteries


Ophthalmic Artery

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Veins


Lymph Vessels

No lymph vessels or nodes are present in the orbital cavity.

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Extrinsic Muscles Producing Movement of the Eye

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Action of individual muscles (anatomical action)


Movement of eye when testing specific muscle (clinical testing).


Movement of eye when testing specific muscle (clinical testing).

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Fascial Sheath of the Eyeball

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• Surrounds the eyeball from the optic nerve to the corneoscleral junction.

• Separates the eyeball from the orbital fat and provides it with a socket for free movement.

• It is perforated by the tendons of the orbital muscles and is reflected onto each of them as a tubular sheath.


Fascial Sheath of the Eyeball

• The sheaths for the tendons of the medial and lateral recti are attached to the medial and lateral walls of the orbit by triangular ligaments called the medial and lateral check ligaments.

• The lower part of the fascial sheath, which passes beneath the eyeball and connects the check ligaments, is thickened and serves to suspend the eyeball; it is called the suspensory ligament of the eye.

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Eyeball

Fibrous coat

Sclera

Cornea

Vascular pigmented coat

The Choroid

Outer pigmented layer

Inner vascular layer

The Ciliary Body

Ciliary ring

Ciliary processes

Ciliary muscle Iris

Nervous coat

Outer pigmented layer

Inner nervous layer


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Ciliary body

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Contents of the Eyeball

Aqueous Humor

Vitreous Body

The Lens


Lens and zonula ciliaris

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Eye Trauma

• The eyeball is protected anteriorly only from large objects, such as tennis balls, which tend to strike the orbital margin but not the globe.

• The bony orbit provides no protection from small objects, such as golf balls, which can cause severe damage to the eye.

• The orbital margins shows that it is least protected from the lateral side.

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