Orbits

Question 1

Treatment for Traumatic Hyphema

a) topical cycloplegics
b) carbonic anyhdrase inhibitors
c) beta blockers
d) Versed
e) A and B

Answer 1

Topical cycloplegics and carbonic anhydrase inhibitors to decrease intraocular pressure.

Question 2

Long-term consequences of hyphema leading to blindness

Answer 2

Corneal staining and glaucoma

Question 3

Cycloplegic drugs have what mechanism of action? Pleas provide examples of this class of drug

Answer 3

Cycloplegic drugs are generally muscarinic receptor blockers. These include atropine, cyclopentolate, homatropine, scopolamine and tropicamide

Question 4

Distance from anterior lacrimal crest to…
Anterior ethmoidal foramen
Posterior ethmoidal foramen
Optic Canal

Answer 4

to anterior ethmoid foramen 24mm
to posterior ethmoidal foramen 36mm
to optic canal 42mm

Question 5

Telecanthus is different from hypertelorism in that there is only an increase in once of the following

a) Outer canal distance
b) Inner canthal distance
c) Interpupillary distance

Answer 5

B) Inner Canthal distance is increased in telecanthus.

In Hypertelorism, the OCD, ICD, and IPD are all increased

Question 6

Telecanthus is associated with syndromes such as

Answer 6

Down syndrome, FAS, Cri du Chat, Klinefelter, Turner, adnd Ehlers Danlos

Question 7

Hypertelorism is not typically associated with syndromes, but rather with

Answer 7

Craniofacial clefts, craniofacial dysplasia, and craniosynostoses syndromes

Question 8

Which of these is true lateralization of the orbit?

Telecanthus or Hypertelorism

Answer 8

Hypertelorism

Question 9

A medial canthopexy is the treatment for

a) telecanthus
b) hypertelorism

Answer 9

Telecanthus, as this only involves inner canthal distance increase

Question 10

Patient’s with a previous history of orbital floor reconstruction are at a (higher or lower) risk for globe rupture because the orbital floor is (more or less) likely to fracture

Answer 10

Patient’s with a previous history of orbital floor reconstruction are at a higher risk for globe rupture because the orbital floor is less likely to fracture

Question 11

Consensual light reflex test is the best method for diagnosis of what?

Answer 11

Relative afferent pupillary defect, or Marcus-Gunn pupil.

Illumination of one eye that results in failure to constrict pupils of both eyes is suggestive of a RAPD

Question 12

What is the instrument used to measure intra-ocular pressure?

Answer 12

A tonometer measures intra-ocular pressure

Question 13

An extremely lower reading on a tonometer could suggest…

Answer 13

An extremely low reading on a tonometer could suggest a glob rupture

Question 14

Normal tonometer range

Answer 14

11-20mm Hg is a normal IOP

Question 15

An elevated tonometer reading could suggest…

Answer 15

An elevated IOP could suggest a retrobulbar hematoma

Question 16

The red color saturation test is a measure of what?

Answer 16

The red color saturation test is the best measure of optic nerve function.
A red object is held in front of each eye separately and the patient is asked whether the object has the same hue (color) and intensity (brightness) in each eye.

Question 17

Monocular diplopia is the anatomical result of…

Answer 17

Monocular diplopia is the result of retinal detachment or lens dislocation

Question 18

Binocular diplopia is commonly seen secondary to…

Answer 18

Edema, neuromuscular paralysis, or extraocular muscle entrapment

Question 19

The Hertel exophthalmeter utilizes what region of the face to measure globe position based on the surrounding bone

Answer 19

The Hertel exophthalmeter utilizes the zygomaticofrontal region

Question 20

The Naugel exophthalmeter utilizes what region of the face to measure globe position based on the surrounding bone

Answer 20

The naugel exophthalmeter utilizes the frontal bone

Question 21

Absolute indications for surgical repair of an orbital floor fracture

Answer 21

1. Globe malposition with enophthalmos
2. Muscle entrapement with resulting diplopia
3. Obital floor “trap door” fracture that has elicited the occulocardiac reflex

Question 22

Contraindications for surgical repair of an orbital floor fracture

Answer 22

1. Any condition that puts the globe at injury (hyphema, retinal tears, lens displacement)
2. The status of the noni-njured eye. What if the patient is blind in one eye or only has one eye?

Question 23

Grading of hyphema

Answer 23

Vertical filling of anterior chamber of the eye Grading system 
Grade I: <1/3 
Grade II: 1/3 - 1/2 
Grade III: 1/2 to near total
Grade IV: Total filling

Question 24

What is the nickname for Grade IV hyphema

Answer 24

Eight ball (the anterior chamber of the eye is completely filled with blood

Question 25

Clinical findings associated with superior orbital fissure syndrome

Answer 25

1. Loss of forehead sensation 2. Loss of corneal reflex 3. Ophthalmoplegia 4. Upper lid ptosis 5. Edema (secondary to venous obstruction) 6. Proptosis

Question 26

What is the difference between superior orbital fissure syndrome and orbital apex syndrome?

Answer 26

Orbital apex syndrome involves the optic nerve, causing loss of vision. So, orbital apex syndrome has the same findings of superior orbital fissure syndrome, plus loss of vision. 1. Loss of forehead sensation 2. Loss of corneal reflex 3. Ophthalmoplegia 4. Upper lid ptosis 5. Edema (secondary to venous obstruction) 6. Proptosis

Question 27

Average orbital volume

Answer 27

Slightly less than 30ml

Question 28

Average globe volume

Answer 28

7ml

Question 29

What level of enophthalmos can be expected with a 1cm3 increase in orbital volume?

Answer 29

3-4mm

Question 30

What are the two types of ophthalmoplegia?

Answer 30

Chronic progress external and internal ophthalmoplegia Chronic progressive external ophthalmoplegia (CPEO), is a type of eye disorder characterized by slowly progressive inability to move the eyes and eyebrows. It is often the only feature of mitochondrial disease, in which case the term CPEO may be given as the diagnosis. Internal is impairment of horizontal eye movements caused by damage to certain connections between nerve centers in the brain stem

Question 31

Define ophthalmoplegia

Answer 31

Paralysis or weakness of the eye muscles

Question 32

What nerve provides motor function to the inferior rectus muscle?

Answer 32

The oculomotor nerve

Question 33

What nerve provides motor functions to the lateral rectus muscle?

Answer 33

The abducens nerve (CN VI)

Question 34

What nerve provides motor function to the superior oblique muscle?

Answer 34

The trochlear nerve (CN IV)

Question 35

What is the Gray Line?

Answer 35

The gray line is the pretarsal orbicularis oculi muscle on the eyelid margin. When placing a Frost suture, the suture is passed through the gray line

Question 36

What is another name for the Gray line

Answer 36

The muscle of Riolan

Question 37

What is a meibomian gland?

Answer 37

Meibomian glands are the tiny oil glands which line the margin of the eyelids (the edges which touch when the eyelids are closed). These glands secrete oil which coats the surface of our eyes and keeps the water component of our tears from evaporating (drying out)