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Padmaja Sudhakar MD
Asst Professor Neurology
University of Kentucky
ANATOMY OF THE ORBIT
ANATOMY OF ORBIT
Seven bones make up the orbit
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Roof - frontal bone & the lesser wing of sphenoid
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Floor – maxilla, zygomatic bone, palatine bone
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Medial wall - maxilla, lacrimal bone, ethmoid , sphenoid
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Lateral wall - zygomatic, greater wing of sphenoid
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Medial walls are parallel, lateral walls form an angle of 900
ANATOMY OF ORBIT
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Superior Orbital Fissure/Orbital Apex
• Contiguous with the cavernous sinus
• Transmits– III, IV, VI, V1, sympathetics, superior ophthalmic vein.
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Annulus of Zinn – origin of recti muscles
Optic canal transmits the optic nerve & ophthalmic artery
ANATOMY OF EXTRAOCULAR MUSCLES
EXTRAOCULAR MUSCLES
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Six extraocular muscles
4 recti- superior, inferior, medial, lateral
2 obliques – superior, inferior
Inferior oblique- thinnest
Medial rectus – largest
EXTRAOCULAR MUSCLES
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Recti run forward within sheaths , pierce the posterior tenon’s capsule &
insert on the anterior sclera at points variably posterior to the corneal
limbus – Spiral of Tillaux
Tenon’s capsule - connective tissue that surrounds the eyeball &
extends to the optic nerve.
EXTRAOCULAR MUSCLES
Superior oblique
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Origin – Trochlea (pulley like structure)
Runs anteriorly in the superior medial orbit to trochlea
Tendon reverses direction
Inferior oblique – anterior inferior medial periorbita near lacrimal fossa
Both obliques insert on the posterior lateral aspect of globe behind the
equator
EXTRAOCULAR MOVEMENTS
Ductions - Monocular eye movements
Versions - Movement of both eyes in the same direction
Vergences are movements of the eyes in opposite directions
Yoke muscles are the primary muscles in each eye that
accomplish a given version (eg, for right gaze, the right
lateral rectus and left medial rectus muscles)
ACTIONS OF EOMS
Medial rectus
Adducts the eye or moves eye towards the nose
 Lateral rectus
Abducts the eye or moves the eye horizontally to
the outside
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ACTIONS OF EOMS
Superior rectus
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Primary action –elevation
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Secondary action (globe adducted) – intortion, adduction
Inferior rectus
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Primary action – depression
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Secondary action (globe adducted)- extortion, adduction
ACTIONS OF EOMS
Superior oblique
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Primary action – intortion, abduction
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Secondary action (globe adducted) – depression
Inferior oblique
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Primary action – extortion, abduction
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Secondary action (globe adducted)- elevation
INNERVATION
3rd cranial nerve
Superior division– levator, superior rectus,
medial rectus
Inferior division -inferior rectus, inferior oblique
 4th cranial nerve – superior oblique
 6th cranial nerve – lateral rectus
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ANATOMY OF THE CAVERNOUS SINUS
CAVERNOUS SINUS
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Complex plexuses of veins in the dura
Located lateral to the sphenoid sinus
Extends from the SOF to the apex of the petrous temporal bone
Lateral wall of the sinus – III, IV & V1 nerve
Internal carotid artery ,VI nerve (lateral) run in the sinus
PATHOLOGY
DIPLOPIA
Reported as double vision or blurred vision
 Does diplopia resolve when one eye is covered?
 Monocular vs binocular
 Is the diplopia horizontal,vertical or oblique?
 Is it same in all fields of gaze (comitant) or vary
with gaze direction (incomitant)
 Is it constant, intermittent or variable?
DIPLOPIA
Monocular- optical – refractive error,
cataract, rarely maculopathy
 Binocular
Orbital Mass
Muscle
Neuromuscular junction
Nerve
Cavernous sinus
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ORBITAL MASS
Intraconal
Primary
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Cavernous hemangioma
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Optic nerve glioma
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Optic nerve meningioma
 Rhabdomyosarcoma
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Orbital varices
Metastatic lesions
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Breast
 Lung
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Prostate
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Neuroblastoma
ORBITAL MASS
Extraconal
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Superior orbit (roof/frontal sinus)
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Dermoid tumor
Mucocoele (frontal sinus)
Orbital encephalocoele
Fibrous dysplasia
Lacrimal gland tumors
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ORBITAL MASS
Extraconal
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Inferior orbit (maxillary sinus/floor)
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Maxillary sinus mucocoele
Fungal sinusitis
Primary tumor (benign or malignant)
Secondary tumor
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ORBITAL MASS
Extraconal
Medial orbit (ethmoid /sphenoid sinus)
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Rhabdomyosarcoma
Carcinoma of sinus
Mucocoele
ORBITAL MASS
Extraconal
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Lateral orbit (pterygopalatine fossa)
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Metastasis
Pseudotumor of orbit
Hemangioma
Meningioma
Rhabdomyosarcoma
Arteriovenous malformations
Encephalocoele
Fibrous dysplasia
Trauma with hemorrhage
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MUSCLE
Mechanical limitation of range of eye movements
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Thyroid associated orbitopathy
Orbital myositis
Orbital trauma
Post – surgery restriction (cataract extraction)
Genetic extraocular myopathy
Congenital fibrosis syndrome
Neoplastic infiltration
Brown syndrome
NERVE
3rd cranial nerve
Superior division – Levator, superior rectus,
medial rectus
Inferior division –inferior rectus, inferior
oblique
 4th cranial nerve – superior oblique
 6th cranial nerve – lateral rectus
 Apex syndrome – CN 2, 3, 4, 6 all together
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CAVERNOUS SINUS
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CN 3, 4, 6, V1, and sympathetics
When limited to 3, 4, 6 difficult to distinguish
cavernous sinus from orbital apex
Fifth nerve involvement – facial
hypoaesthesia
Sympathetic involvement - Horner’s
syndrome
NEUROMUSCULAR JUNCTION
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Myasthenia Gravis
• Fluctuating /variable ptosis or diplopia,
ductional deficits
• Bilateral orbicularis weakness
A. 6th nerve palsy B. INO
C. Myasthenia
D. Duanes Type 1
DUANES RETRACTION
SYNDROME TYPE 1
 Congenital absence of 6th nerve/nucleus
 Orthophoric in primary
 Esotropic on lateral gaze with limited abduction
 No diplopia despite misalignment
DUANES RETRACTION
SYNDROME TYPE 1
Palpebral fissure narrows and globe retracts on adduction
A. Myasthenia
B. INO
C. Duanes Type 2
D. 3rd nerve palsy
DUANES RETRACTION
SYNDROME TYPE 2
• Orthophoric in primary
• Exotropic on lateral gaze and limited
adduction
• Palpebral fissure
narrows and
globe retracts on adduction
• No diplopia despite misalignment
A. Gaze palsy
C Myasthenia gravis
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B. 1 ½ syndrome
D. Duanes Type 3
DUANES RETRACTION
SYNDROME TYPE 3
• Orthophoric in primary
• Limited abduction and adduction
• Palpebral fissure narrows and
globe retracts on adduction
• No diplopia despite misalignment
A. MG
C. CPEO
B. Duanes Syndrome
D. Mobius
CHRONIC PROGRESSIVE
EXTERNAL OPHTHALMOPLEGIA
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Bilateral ptosis and
ophthalmoplegia
Progresses over
years
Can be asymmetric
Mitochondrial
myopathy
Check EKG
Review MR
A. Myasthenia gravis B. Multiple sclerosis
C. Orbital process
D. Tolosa-Hunt
EOM METASTASIS FROM
BREAST CANCER
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Review the PMH
Orbital signs are not always
present with an orbital process
A. Myasthenia
C. TED
B. 3rd nerve palsy
D. Aberrant Regeneration
THYROID EYE DISEASE
A. CPEO
C. Myasthenia
B. 3rd nerve palsy
D. Orbital Process
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SLEEP TEST – take a nap while you
wait for the doctor