Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pediatrics > Strabismus > Flashcards

Strabismus Flashcards

1
Q

How long are rectus muscles?

A

40mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Longest overall muscle + tendon

A

SO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Shortest overall muscle + tendon

A

IO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Origin of IO

A

behind lacrimal fossa (periosteum of maxillary bone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which muscles do nor originate from annulus of zinn?

A

SO, IO, levator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

2ndary action of vertical recti?

A

torsion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

2ndary action of obliques?

A

elevation or depression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Monofixation syndrome

A
  • binocular sensory state in patient with small angle strabismus (<8pd)
  • central scotoma and peripheral fusion present
  • 4BO prism test: normal eye (no refixation when over normal eye); scotoma eye (no initial eye turn)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Bagolini lenses

A
  • determine retinal correspondence
  • break in line is proportional to size of suppression scotoma
  • right eye lens at 135, left lens at 45
  • fixate on distant light
  • esotropia with NRC: A
  • exotropia with NRC: V
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Criteria for refractive amblyopia

A

High ametropia: +5D, -8D, astigmatism 2.5D

Anisometropia: 1D hyperopia, 3D myopia, 1.5D astigmatism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hering’s law

A

Equal and simultaneous innervation to synergistic muscles

-2ndary deviation larger than primary deviation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Sherrington’s law

A

Innervation to ipsilateral antagonist decreases as innervation to agonist increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Angle kappa

A
  • angle btwn visual axis and anatomic axis (pupillary axis)

- POSITIVE: causes slight temporal rotation of globe (light reflex appears nasal)–> ROB, toxocara

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Congenital esotropia

A
  • present by 6 months
  • increased freq of CP or hydrocephalus
  • usually >30PD
  • assoc with DVD, IOOA (involved eye elevates with adduction), latent nystagmus
  • Sx: BMR recession, MR recession and LR resection of same eye
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Accommodative esotropia

A
  • onset 6mos to 7years
  • assoc with amblyopia (usually from anisometropia)
  • refractive: normal AC/A ratio (tropia within 10pd at distance and near)
  • nonrefractive: high AC/A ration (tropia greater at near, reduced at near with plus lens (consider miotics to treat, bifocals)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

AC/A ratio

A

Normal: btwn 3:1 and 5:1 prism diopters per diopter of accommodation

  • high AC/A when near deviation exceeds distance by >10-15PD
  • AC/A= IPD + [(N-D)/accom demand at fixation distance]
  • accom demand 20cm=5D
  • AC/A=(WL-NL)/D
17
Q

Convergence insufficiency

A

Exophoria greater at near than distance

-exacerbated by fatigue, drugs, uveitis, Adies, trauma, systemic illness

18
Q

Convergence paralysis

A
  • normal adduction and accommodation
  • XT and diplopia on attempted near fixation
  • Parinaud’s syndrome: due to intracranial lesion
  • Tx: base-in prisms or occlusion
19
Q

DVD

A
  • intermittent deviation of NONFIXING eye (upward deviation)
  • assoc with early disruption of binocular development
  • does NOT obey hering’s law
20
Q

Bielschowsky’s phenomenon

A
  • DVD

- elevated eye will drift downward when light in fixating eye is reduced

21
Q

IOOA

A

-2/3 of patients with congenital ET
-Bilateral and asymmetric
-when fixing eye abducted, adducting eye is elevated
-when fixing eye adducted, abducted eye is depressed
V PATTERN
-Tx: IO weakening

22
Q

IO palsy

A

LIO palsy: worse left gaze, worse right head tilt
-poor elevation in adduction
-normal forced duction (distinguishes from Brown’s)
A PATTERN
-Tx: IR recession, SO weakening if assoc with SOOA

23
Q

SOOA

A

-depression on attempted adduction
A PATTERN
-Tx: weaken SO with tenotomy or silicone spacer

24
Q

SO palsy

A

With IOOA: weaken ipsilateral IO +/- ipsilateral IR resection or contralateral SR recession
Without IOOA: ipsilateral SR recession or contralateral IR recession
Harada-Ito for torsional component

25
Q

Double elevator palsy (monocular elevation deficiency)

A

-unilateral defect of upgaze assoc with ipsilateral ptosis
-may be supranuclear
2 TYPES
-IR restriction: unilateral fibrosis syndrome
-Elevator weakness (SR and IO)

26
Q

Brown’s syndrome

A

SO tendon sheath syndrome

  • inability to elevate in ADDUCTION
  • V pattern divergence in upgaze
  • no SOOA
  • head posture
  • abrupt downshoot in ADDUCTION
  • restricted forced ductions
  • Tx: SO weakening
27
Q

Treatment of A patterns

A

IO palsy or SOOA

  • MR displacement superorly
  • LR inferiorly
28
Q

Treatment of V patterns

A

IOOA, congenital ET, craniosynostosis

-MR inferiorly, LR superiorly

29
Q

Duane’s retraction syndrome

A

Hypoplasia of 6th nerve nucleus, midbrain pathology, fibrosis of LR
Type 1: limitation of ABDUCTION, retraction in adduction, appears esotropic
Type 2: limitation of ADDUCTION, appears exotropic
Type 3: limitation of ABDUCTION and ADDUCTION
**Avoid muscle resections

30
Q

Mobius syndrome

A

CN 6 and 7 palsies

  • aplasia of involved brainstem nuclei
  • can get exposure keratitis from poor lid closure
31
Q

CPEO

A
  • sporadic or maternal inheritance
  • Associated with Kearns-Sayre, abetalipoproteinemia, refsum’s, oculopharyngeal dystrophy, cardiac conduction defects
  • absent bells phenomenon
32
Q

Kestenbaum procedure

A

Bilateral resection/recession to dampen nystagmus/head turn (eyes surgically moved toward head turn)

Pediatrics (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions