Strabismus

Question 1

What action does the superior rectus have?

Answer 1

elevates, adducts, medially rotates

Question 2

What action does the inferior rectus have?

Answer 2

depresses, adducts, excyclotort (laterally rotate)

Question 3

What does the superior oblique do?

Answer 3

depresses and intorts (medially rotates)

Question 4

What does the inferior oblique do?

Answer 4

elevates and extorts (laterally rotates)

Question 5

What muscles does CN 3 innervate?

Answer 5

medial rectus
inferior rectus
superior rectus
inferior oblique
levator

Question 6

Movements of both eyes, conjugate

Answer 6

versions

Question 7

Disconjugate movements of eyes

Answer 7

vergences

Question 8

Movements of one eye

Answer 8

ductions

Question 9

Misalignment of visual axes

Answer 9

strabismus

Question 10

Latent deviation that appears only when fusion is disrupted

Answer 10

phoria

Question 11

Manifest deviation, beyond the range of fusional control

Answer 11

tropia

Question 12

nasalward deviation of the eye, “crossed eye”

Answer 12

esotropia

Question 13

Temporal deviation of the eye, “walleye”

Answer 13

exotropia

Question 14

Vertical deviation, relative to higher eye

Answer 14

hypertropia

Question 15

Angle of deviation remains constant regardless of direction of gaze; range of motion of eyes is full, without limitation or restriction
Most commonly seen in childhood onset strabismus

Answer 15

concomitant strabismus

Question 16

Angle of strabismus varies with gaze direction; limitation of ocular movements Patient may exhibit abnormal head posture to maintain binocularity
May be congenital or acquired

Answer 16

incomitant strabismus

Question 17

abnormalities of binocularity, motion processing, poor fusional vergences

Answer 17

comitant

Question 18

Developmental (Duanes’, Brown’s), Neurologic (cranial nerve palsy, myasthenia), Restrictive (trauma, thyroid disease)

Answer 18

incomitant

Question 19

What are some ways to diagnose strabismus?

Answer 19

cover test, alternate cover test
light reflex testing
angle of deviation measured with prisms
motility evaluation
sensory testing to assess binocularity

Question 20

common in infants: wide flat nasal bridge and epicanthal folds, normal alignment by light reflex and cover tests

Answer 20

pseudoesotropia

Question 21

autosomal dominant, inelastic muscles and ptosis, positive forced
ductions

Answer 21

congenital fibrosis syndrome

Question 22

lymphocytic infiltration and secondary fibrosis of extraocular muscles in thyroid disease

Answer 22

Graves’ disease

Question 23

scarring/entrapment of orbital tissue/extraocular muscles

Answer 23

orbital fractures

Question 24

microvascular, tumor, trauma, aneurysm

Answer 24

cranial nerve palsies

Question 25

eye down and out, ptosis, +/- pupillary involvement

Answer 25

third nerve palsy

Question 26

oblique diplopia and torsion, bilateral often secondary to trauma

Answer 26

fourth nerve palsy

Question 27

face turn towards affected side

Answer 27

sixth nerve palsy

Question 28

variable strabismus and ptosis, Acetylcholine receptor antibodies, Tensilon test

Answer 28

myasthenia gravis

Question 29

strabismus surgery which weakens effect of operated muscle

Answer 29

recession

Question 30

strabismus surgery which enhances the effect of operated muscle

Answer 30

resection

Question 31

strabismus surgery which shifts the force vector of muscle

Answer 31

transposition