SM_09b: Clinical Anatomy of the Orbit

Question 1

Melbomian glands are ____ and form ____

Answer 1

Melbomian glands are sebaceous and form oily part of tears

Question 2

Blepharitis is ___ that presents with ___, ___, ___, and ___

Answer 2

Blepharitis is chronic inflammation of the lid margin that presents with foreign body sensation, burning, mattering, and redness

Question 3

Stye is ___, while chalazion is ___

Answer 3

Stye is pustule of pilosebaceous apparatus, while chalazion is granulomatous inflammation of eyelid

Question 4

____ and ____ hold the eyelid in place

Answer 4

Medial and lateral canthal tendon hold the eyelid in place

Question 5

Ectropion is ____ resulting from ____

Answer 5

Ectropion is when the eyelid turns outward resulting from a lack of tendon support

Question 6

Entropion is ____ resulting from ____

Answer 6

Entropion is when eyelid turns inward resulting from lack of tendon support

Question 7

Ptosis is ___

Answer 7

Ptosis is droopy eyelid

Question 8

Ptosis etiologies are ____, ____, ____, ____, and ____

Answer 8

Ptosis etiologies are myogenic, neurogenic, aponeurotic, mechanical, and pseudoptosis

• Myogenic (weak muscle): congenital, muscular dystrophies
• Neurogenic (abnormal innervation): Horner’s syndrome (damage to sympathetic chain), 3rd nerve palsy, myasthenia gravis (ACh receptor abnormality)
• Aponeurotic (stretched tendon): involutional, traumatic
• Mechanical (weighted down lid)
• Pseudoptosis (excess skin, not really ptosis)

Question 9

Test for neurogenic ptosis by ____ and ____

Answer 9

Test for neurogenic ptosis by motility exam and comparing pupil size in dim illumination and bright illumination

Question 10

Horner’s syndrome is a cause of ____ due to ____ that presents as ____ and ____

Answer 10

Horner’s syndrome is a cause of neurogenic ptosis due to loss of sympathetic tone that presents as ptotic lid and miotic pupil (weak dilator)

Question 11

Third nerve palsy is a cause of ____ that presents as ____ due to ____

Answer 11

Third nerve palsy is a cause of neurogenic ptosis that presents as dilated pupil due to loss of parasympathetic tone to constrictor muscle

(weak superior rectus, weak inferior rectus, weak medial rectus, and weak inferior oblique)

Question 12

Proptosis is also called ____ and is ____

Answer 12

Proptosis is also called exophthalmos and is bulging eye

Question 13

Proptosis occurs when ____ due to ____, ____, ____, and ____

Answer 13

Proptosis occurs when eye is pushed out from volume expansion in a limited space due to Graves orbitopathy, vascular congestion, cellulitis, or orbital tumor

Question 14

Complains of dry eyes and her eyes bulging out. Diagnosis is _____

Answer 14

Complains of dry eyes and her eyes bulging out. Diagnosis is Graves orbitopathy

(would want to know about onset, thyroid studies, and if she smokes)

(much more fat in eye so eyeball gets pushed forward)

Question 15

Describe imaging used in Graves disease

Answer 15

Imaging used in Graves disease

• CT scan: images bone well to evaluate apical compression in addition to good muscle resolution, valuable in surgical planning, use if unilateral / atypical or evidence of neuropathy or diplopia (not for all)

Question 16

___ is a barrier to infection in the eye

Answer 16

Orbital septum is a barrier to infection in the eye

Question 17

Preseptal cellulitis is caused by ____, ____, ____, or ____ and can be treated ____

Answer 17

Preseptal cellulitis is caused by cut, trauma, hordeolum (stye), and hematogenous and can be treated as an outpatient

Question 18

Orbital cellulitis is caused by ____, ____, ____, and ____ and is treated ____

Answer 18

Orbital cellulitis is caused by sinus disease, penetrating wound, hematogenous, or preseptal cellulitis and is treated by admission for IV antibiotics

(life threatening)

Question 19

Infection from ____ can spread to orbit

Answer 19

Infection from ethmoid sinus can spread to orbit

Question 20

Orbital infection is imaged with ___ to highlight ___ and ___

Answer 20

Orbital infection is imaged with contrast to highlight inflammation and abscess formation

Question 21

CT allows investigation of ____ changes in lacrimal lesions

Answer 21

CT allows investigation of bone changes in lacrimal lesions

Question 22

CT scans identify ____ and ____ better than MRI which is useful for retinoblastoma

Answer 22

CT scans identify calcium and bone better than MRI which is useful for retinoblastoma

Question 23

MRI is good at evaluating ____

Answer 23

MRI is good at evaluating CNS tumors

(gadolinium aids in detection)

Question 24

____ and ____ of orbit have weak bone

Answer 24

Medial wall and floor of orbit have weak bone

Question 25

Orbital floor fracture can ____ because the ____ muscle is in the floor

Answer 25

Orbital floor fracture can limit upgaze because the inferior rectus muscle gets trapped

(inferior rectus is in the orbital floor)