Padmaja Sudhakar MD Asst Professor Neurology University of Kentucky How do the eyes move? Padmaja Sudhakar MD Asst Professor Neurology University of Kentucky

Welcome to the efferent system

ANATOMY OF THE ORBIT

ANATOMY OF ORBIT Seven bones make up the orbit Roof - frontal bone & the lesser wing of sphenoid Floor – maxilla, zygomatic bone, palatine bone Medial wall - maxilla, lacrimal bone, ethmoid , sphenoid Lateral wall - zygomatic, greater wing of sphenoid Medial walls are parallel, lateral walls form an angle of 900

ANATOMY OF ORBIT Superior Orbital Fissure/Orbital Apex Contiguous with the cavernous sinus Transmits– III, IV, VI, V1, sympathetics, superior ophthalmic vein. Annulus of Zinn – origin of recti muscles Optic canal transmits the optic nerve & ophthalmic artery

ANATOMY OF EXTRAOCULAR MUSCLES

EXTRAOCULAR MUSCLES Six extraocular muscles 4 recti- superior, inferior, medial, lateral 2 obliques – superior, inferior Inferior oblique- thinnest Medial rectus – largest

EXTRAOCULAR MUSCLES 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 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

ACTIONS OF EOMS Superior rectus Primary action –elevation Secondary action (globe adducted) – intortion, adduction Inferior rectus Primary action – depression Secondary action (globe adducted)- extortion, adduction

ACTIONS OF EOMS Superior oblique Primary action – intortion, abduction Secondary action (globe adducted) – depression Inferior oblique Primary action – extortion, abduction 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

ANATOMY OF THE CAVERNOUS SINUS

CAVERNOUS SINUS 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

ORBITAL MASS Intraconal Primary Cavernous hemangioma Optic nerve glioma Optic nerve meningioma Rhabdomyosarcoma Orbital varices Metastatic lesions Breast Lung Prostate Neuroblastoma

ORBITAL MASS Extraconal Superior orbit (roof/frontal sinus) Dermoid tumor Mucocoele (frontal sinus) Orbital encephalocoele Fibrous dysplasia Lacrimal gland tumors

ORBITAL MASS Extraconal Inferior orbit (maxillary sinus/floor) Maxillary sinus mucocoele Fungal sinusitis Primary tumor (benign or malignant) Secondary tumor

ORBITAL MASS Extraconal Medial orbit (ethmoid /sphenoid sinus) Rhabdomyosarcoma Carcinoma of sinus Mucocoele

ORBITAL MASS Extraconal Lateral orbit (pterygopalatine fossa) Metastasis Pseudotumor of orbit Hemangioma Meningioma Rhabdomyosarcoma Arteriovenous malformations Encephalocoele Fibrous dysplasia Trauma with hemorrhage

MUSCLE Mechanical limitation of range of eye movements 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

CAVERNOUS SINUS 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 Myasthenia Gravis Fluctuating /variable ptosis or diplopia, ductional deficits Bilateral orbicularis weakness

A. 6th nerve palsy B. INO ? C. Myasthenia D. Duanes Type 1 29

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 30

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 32

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 33

? A. Gaze palsy B. 1 ½ syndrome C. Myasthenia gravis D. Duanes Type 3 34

DUANES RETRACTION SYNDROME TYPE 3 Orthophoric in primary Limited abduction and adduction Palpebral fissure narrows and globe retracts on adduction No diplopia despite misalignment 35

? A. MG B. Duanes Syndrome C. CPEO D. Mobius

CHRONIC PROGRESSIVE EXTERNAL OPHTHALMOPLEGIA Bilateral ptosis and ophthalmoplegia Progresses over years Can be asymmetric Mitochondrial myopathy Check EKG Review MR 41

? A. Myasthenia gravis B. Multiple sclerosis C. Orbital process D. Tolosa-Hunt 42

EOM METASTASIS FROM BREAST CANCER Review the PMH Orbital signs are not always present with an orbital process

? A. Myasthenia B. 3rd nerve palsy C. TED D. Aberrant Regeneration 44

THYROID EYE DISEASE

? A. CPEO B. 3rd nerve palsy C. Myasthenia D. Orbital Process

SLEEP TEST – take a nap while you wait for the doctor

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