Pediatrics 3

Question 1

What is the shortest rectus muscle (including tendon length)?

Answer 1

Medial rectus (remember the medial wall is the shortest)

Question 2

Posterior fixation of EOM to sclera 11-18 mm from insertion of an EOM (without disinserting the muscle) describes what procedure?

Answer 2

Fadenoperation (not thought to work all that well)

Question 3

In testing for ARC, the more dissociative the test (e.g afterimage test) the more likely to pick up ARC or NRC?

Answer 3

NRC; the less dissociative (e.g. Baglioni striated glasses) the more likely to pick up ARC as this is more representative of real life vision)

Question 4

What is a normal AC/A ratio?

Answer 4

5-Mar

Question 5

Delayed visual maturation (DVM) is classified as inability to fixate and follow by how many months?

Answer 5

3 months

Question 6

Divergence insufficiency is a type of acquired nonaccomodative esotropia that is characterized by what?

Answer 6

Esotropia that is greater at distance

Question 7

Aside from myotonic dystrophy, what can cause a “christmas tree cataract”?

Answer 7

Hypoparathyroidism

Question 8

V pattern is associated with what type of muscle dysfunction?

Answer 8

Apparent superior oblique dysfunctionYou get over elevation in adduction

Question 9

Which type of alphabet strabismus is more common?

Answer 9

V pattern

Question 10

If an A or a V pattern strabismus is thought to be due to apparent overreaction of the one of the oblique muscles, what type of procedure would you want to do?

Answer 10

Oblique weakening procedure

Question 11

If an A or V pattern strabismus is thought to be due to horizontal muscles (no apparent oblique overaction), what type of surgery would you want to do?

Answer 11

Horizontal muscle transposition surgery applying the MALE mnemonic (these apply for weakening or strengthening procedures

Question 12

What is Bielkowski phenomenon?

Answer 12

In DVD, decreasing illumination of fixated eye will cause non-fixating eye with DVD to drift down. Opposite is also true, when increasing illumination in fixated eye, non-fixating eye will drift up.

Question 13

What causes dissociative complexes (DVD, DHD, DTD)?

Answer 13

Thought to be early disruption of binocular vision

Question 14

What is the most common type of deviation in craniosynostosis syndromes?

Answer 14

V pattern exotropia

Question 15

Which condition is classically associated with dissociated nystagmus?

Answer 15

INO

Question 16

limitation of upward gaze with a hypotropia that is similar in adduction and abduction +/- ptosis describes what vertical muscle disorder?

Answer 16

Monocular elevation deficiency; unknown etiology

Question 17

What direction does the eye shift in DVD?

Answer 17

upward and outward with excylotorsion; this occurs when the other eye is occluded or during period of visual inattentiveness.

Question 18

Is DVD usually bilateral or unilaterl?

Answer 18

bilateral but frequently assymetric

Question 19

Which law does DVD/DHD break?

Answer 19

Herrings law

Question 20

What innervation anomoly is present in Duane retraction syndrome?

Answer 20

Aberrant innervation of the lateral rectus by CN III in the presence of aplasia of CN IV nucleus.

Question 21

What are the three types of Duane syndrome?

Answer 21

Type 1: limitation of abduction + esotropia Type 2: limitation of adduction + exotropiaType 3: limitation of abduction and adduction with ET or XT or no deviation in primary

Question 22

Which type of Duane is most common?

Answer 22

Type 1

Question 23

Which movement causes retraction in Duane retraction syndrome?

Answer 23

adduction of the involved eye (this is a unilateral condition)

Question 24

What is the cause of congenital fibrosis of the extraocular muscles?

Answer 24

developmental defects of cranial nerve nuclei and of the nerves themselves that leads to fibrosis and restriction of the EOM’s (all or some can be involved)

Question 25

Is the most common cause of Brown syndrome acquired or congenital?

Answer 25

congenital

Question 26

Paradoxical inversion of the OKN response is pathgnomonic for what?

Answer 26

Infantile nystagmus syndrome

Question 27

What does the term nystagmus blockage syndrome mean?

Answer 27

A patient with infantile nystagmus who converges to reduce nystagmus and in so doing causes an esotropia

Question 28

Is infantile nystagmus syndrome associated with systemic CNS abnormalities?

Answer 28

No, usually good vision too

Question 29

How are the wave forms (slow phase particularly) different in infantile nystagmus syndrome vs latent nystagmus?

Answer 29

INS: exponentially accelerating slow phaseLN: exponentially decelerating slow phase

Question 30

What is the triad characteristic of spasmus mutans?

Answer 30

1. small-amplitude, high frequency nystagmus2. Head nodding 3. Torticollis

Question 31

Prisms to correct nystagmus should have apex or base towards the null point?

Answer 31

Apex towards the null point

Question 32

What is an advantage of the hang-back recession vs typical recession?

Answer 32

Do not have to suture to sclera and risk perforation. Sutures are placed to the cut rectus muscle stump and hung back the desired amount

Question 33

For vertical deviations is a recession or resection usually preferred initially?

Answer 33

recession

Question 34

How much does 1mm of resection or recession fix a vertical deviation?

Answer 34

3 PD approximately

Question 35

SO tendon tucking and the Harada-Ito procedures are ways to fix what type of strabismus?

Answer 35

SO palsy or weakness

Question 36

Which slipped muscle is the hardest to recover?

Answer 36

MR

Question 37

Pulled-in-two syndrome (dehiscence of muslce usually at muscle tendon junction) is most frequent in which EOM?

Answer 37

IR

Question 38

What does bupivacaine injection into EOM do?

Answer 38

It causes a chemical resection effect, opposite that of botox which provides a chemical recession effect

Question 39

Brachycephaly is usually due to closure of what sutures?

Answer 39

B/l coronal, causing shorter AP axis

Question 40

Scaphocephaly is usually due to closure of what sutures?

Answer 40

Sagital suture causing boat like shape (longer AP axis)