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Motility > Block 12 > Flashcards

Block 12 Flashcards

1
Q

What is nystagmus

A

Involuntary rhythmic oscillation of one or both eyes

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2
Q

What can nystagmus be a sign of

A

Visual pathway lesion

Ocular control abnormality

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3
Q

What are the characteristics of nystagmus

A 
Movement in all gazes
Convergence
Unilateral/bilateral
Conjugate of disconjugate
Congenital or acquired

Shakingm dancing, jerking, wobbling eyes

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4
Q

What is jerk

A

Both quick and slow components.
There is a fast corrective sacade to bring the eye back to the target

Characterized by the direction of the fast component

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5
Q

What is pendular

A

To and fro movement of equal velocity in each direction

A sinusoidal movement without a fast phase

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6
Q

T/F jerk nystagmus is characterized by the fast phase, but the slow phase of the nystagmus reflects the abnormality

A

True

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7
Q

What are the directions/movements of nystagmus

A

Horizontal
Vertical
Torsional
Combination

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8
Q

What is the amplitude of nystagmus

A

the size/extent of movement between the start and drift away from fixation to start of the corrective movement

Distance travelled during the movement

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9
Q

What is the frequency of nystagmus

A

Number of oscillations per unit of time

1 Hz

The greater the number of beats the higher the frequency

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10
Q

Frequency > 2Hz

A

Fast nystagmus

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11
Q

Frequency <2 Hz

A

Slow nystagmus

Need slit lamp to see

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12
Q

What is the null point

A

Where the intensity of the nystagmus diminishes and VA improves. This may be associated with an anomalous head movement

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13
Q

What does occlusion do to nystagmus

A

The fast phase is towards the uncovered eye
Amplitude and frequency increase

Latent component usually indicates a congenital condition

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14
Q

What are some causes of nystagmus

A

Genetics
Developmental abnormalities
Ocular pathology/conditions

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15
Q

What are some anterior segment conditions associated with nystagmus

A

Congenital cataract
Congenital glaucoma
Iridocorneal dysgenesis

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16
Q

What foveal disease can nystagmus be associated with

A

Foveal hypoplasia

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17
Q

What optic nerve disorders are associated with nystagmus

A

Coloboma
Optic nerve hypoplasia
Toxoplasmosis

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18
Q

What are physiological nystagmus

A

Endpoint EOM
Rotational
Caloric
OKN

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19
Q

What are pathological nystagmus

A 
Congenital
Latent/manifest
Acquired
Spasmus nutans
Vestibular 
Gaze paretic
See-saw
Convergence-retraction
Downbeat
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20
Q

What do you want to know on case history

A

Onset?
Any associated condtions
Variable frequency/amplitude/head position/ null point, head nodding

Any symptoms?

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21
Q

What are some symptoms of nystagmus

A 
VA
Asthenopia
Blurred vision
Diplopia
HA
Vertigo
Oscillopsia
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22
Q

What can perinatal history tell you

A

Is there was a developmental issue that caused it

If there was labor and delivery issues, maternal infections, prematurity, was mom on any medications

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23
Q

T/F children with congenital nystagmus always complain of problems?

A

False, they rarely do

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24
Q

How is VA affected in nystagmus

A

It varies from normal to severely impaired depending on the cause
20/30-20/400

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25
Q

Which will cause less VA loss? Motor coordination problem or sensory issues?

A

Motor coordination problems

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26
Q

Marked decreased VA is more likely in….

A

Sensory, retinal, optic nerve abnormalities

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27
Q

How should you evaluate VA

A 
D and N
D>N
Monocular
Binocular
Chart depends on the age
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28
Q

What is seen during monocular VA when one eye is covered

A

Latent nystagmus may manifest

Jerk nystagmus intensity increases with the fast phase in the direction of the uncovered eye

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29
Q

For nystagmus you need to evaluate VA without dissociating the eyes or use a plus lens to blur. What lens should be used?

A

+2-+5

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30
Q

How is nystagmus affected by refractive error

A

All nystgmus patients should be evaluated for significant error

Correction can improve sensory and motor fusion

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31
Q

How should you evaluate VA in nystagmus

A

Cycloplege
Have pt look towards their null point

Use trial lenses or lens bar, do not use phoropter

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32
Q

How should you evaluate binocular vision

A

Move the eyes in 9 gazes
Look at pupils
Hirschberg/krimsky- see if corneal reflex is even

Bruckners
CT (use a +5D lens instead of paddle)
MEM

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33
Q

What is stereo and sensory testing like in nystagmus patients

A

Variable
Stereo will let you see if pt has a phoria

Do worth 4 dot for suppression

Saccades and pursuits

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34
Q

How would you assess IOP in nystagmus patients

A

NCT or tonopen

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35
Q

Why is VF testing hard in nystagmus

A

Because of their change in fixation

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36
Q

What will slit lamp allow you to see in nystagmus

A

See pattern
Indicate and detect presence of coloboma or transillumination

Need to dilate

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37
Q

OCT the fovea in nystagmus to identify what

A

Subtle fovea hypoplasia

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38
Q

T/F recent onset and/or systagmus that has not been diagnosed need neuro referrals

A

True

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39
Q

What is oscillopsia

A

Sensation of the environment moving

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40
Q

What is vertigo

A

Feeling of being off balance

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41
Q

What is null point

A

Position of gaze where the eyes are quiet

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42
Q

What is physiological nystagmus

A

Conjugate

Jerk nystagmus without other symptoms or decreased vision

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43
Q

Endpoint nystagmus has _____ amplitude, ________ frequency

A

Small amp

Variable freq

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44
Q

How does endpoint nystagmus appear

A

Intermittent conjugate jerk
Fast phase is in the direction of gaze
Can be worse when tired
Seen in bth eyes with extreme lateral gaze held for a prolonged time

Symmetrical in right and left gaze

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45
Q

What is rotational nystagmus

A

Jerk nystagmus due to head or body rotation

Related to endolymph in the semicircular canals

Normal response is slow conjugate eye movement then fast phase in the OPPOSITE direction

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46
Q

What is caloric nystagmus

A

Conjugate jerk nystagmus produced during the caloric testing of the vestibular system

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47
Q

What is the caloric test

A

Use of warm and cold water to set up temperature gradients in the semicircular canal causing a convection current in the endolymph, stimulating hair cels

COWS

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48
Q

Cold water in caloric test causes

A

Nystagmus fast phase towards opposite ear

49
Q

Warm water caloric test

A

Nystagmus with fast phase towards the ipsilateral ear

50
Q

What is optokinetic nystagmus

A

Slow pursuit eye movement followed by fast corrective saccade because a visual field moves over the retina

It is a conjugate movement maintaining the image of the moving target on the fovea when the head is still

The fast corrective sauced to fixate on a new stripe

51
Q

When does OKN reflex development

A

3-5 months of age

52
Q

What is OKN useful for

A

Malingering

Uncooperative patients

53
Q
  • OKN
A

Inconclusive

54
Q

What does a child with congenial nystagmus show on OKN

A

Reverse OKN response

Could also sow preserved vertical OKN response

55
Q

What are pathological nystagmus show

A

Dissociated movements with excessive oscillations in the presence of other motor abnormalities

56
Q

Who is affected by congenital nystagmus

A

Present at or shortly after birth

Twice as common in boys

Likely have a family history

Can occur in people with strabismus as part of an underlying systemic or visual abnormality

57
Q

What are the etiology of congenital nystagmus

A

Afferent (sensory 40%)

Efferent (motor 60%)

58
Q

How does congenital nystagmus appear

A 
Pendulum/jerk nystagmus*
Horizontal (even in vertical gaze)
Conjugate
NO OSCILLOPSIA
Amp/freq varies
Active fixation, attention, or anxiety can increase nystagmus 
Could have anomalous head posture if null point is not at primary 
Can improve with age
OKN reverse
59
Q

How is VA at null point

A

Very good

The patient will turn or tilt head to decrease nystagmus so the null point will have the best VA

60
Q

Congenital nystagmus _______ with fixation and _____ with convergence

A

Increases

Decreases

61
Q

When do you see latent nystagmus with congenital

A

When one eye is covered

62
Q

Afferent etiology for congenital nystagmus

A

Inadequate image formation that results in failure of development or normal fixation

Severity is correlated to degree of vision loss and pathology

They have poor vision and little prognosis for improvement

63
Q

What should you consider as causes for afferent congenital nystagmus

A

Optic atrophy
Optic nerve hypoplasia
Retinal dystrophy

Albinism
Aniridia
Achromatopsia
Cataracts

64
Q

Efferent etiology in congenital nystagmus

A

Fixedation and/or motor issues

Better VA than nystagmus from afferent causes

Cosmesis concerns

65
Q

What is nystagmus blockage syndrome

A

A patient with congenital nystagmus that later develops esotropia

Develops in patients with congenital nystagmus because of attempts to suppress nystagmus by converging

The esotropia can result with a head turn

Convergence dampens congenital nystagmus

66
Q

When does nystagmus blockage syndrome reduce or disappear

A

On adduction of the fixating eye

67
Q

When does nystagmus blockage syndrome increase

A

As fixating eye moves toward primary or into abduction

68
Q

What can nystagmus blockage syndrome look like

A

CN6 palsy

But they CAN abduct the eye

69
Q

What is latent nystagmus

A

Congenital

JERK nystagmus after occlusion of one eye

70
Q

How does latent nystagmus appear

A

Horizontal
Fast phase towards the uncovered eye
Benign and isolated
Can be associated with strabismus and amblyopia

Increased with disruption of fusion
Monocular VA decreased
Bingo VA is better
Can be present with other forms of nystagmus

71
Q

T/F latent nystagmus can also occur with both eyes open but one eye is suppressed.

A

True

72
Q

What is spasmus nutans

A 
Starts shortly after birth
Pendulum nystagmus
Bilateral 
Reduces by age 5-8
No long term sequelae-often benign

Can be associated with strabismus, amblyopia and developmental delays

73
Q

What are the characteristics of spasmus nutans

A 
Small fine ampl
High frequ/fast
Head nodding
Torticollis
Head nodding and torticollis appears to be compensatory
74
Q

Why is spasmus nutans a neuro referral

A

Because you want to make sure they don’t have chiasmal tumors, gloomy, craniopharyngioma, and retinal dystrophies, want to check for optic nerve abnormalities

75
Q

What is seen-saw nystagmus

A

Pendular
One eye elevates and intorts while the other depresses and extorts
(The eyes alternate movements)

76
Q

What I️s see-saw nystagmus associated with

A

Lesson in suprasellar area
Craniopharyngioma in children
Joubert syndrome

Needs neurology and radiology

77
Q

What is downbeat nystagmus

A

Jerk vertical nystagmus n primary, fast phase beats down

Neuro consult

78
Q

What is down beat nystagmus due to

A

Craniopharyngioma-cervical junction abnormalities
Chiari malformation
Medications (lithium, tranquilizers)

79
Q

What is upbeat nystagmus

A

Jerk vertical nystagmus with fast phase up

80
Q

What causes upbeat nystagmus

A

Brainstem abnormalities

Drugs

81
Q

What is vestibular nystagmus

A

Horizontal JERK with a rotary element

Oscillopsia, nausea, vertigo, hearing loss

82
Q

What is vestibular nystagmus associated with

A

Inner ear or vestibular abnormalities

Dusyfuntion of the peripheral or central vestibular pathway

83
Q

What is convergence retraction syndrome

A

Rhythmic convergence and retraction of the eyes when attempting upgaze movement

It is not a true nystagmus because it does not have a slow phase, it has opposing addicting saccades

84
Q

What causes retraction in convergence retraction syndrome

A

There is contraction of all EOMs at the same time

85
Q

What is parinaud syndrome

A

Dorsal midbrain syndrome. They have pretectal dysfunction, excess onvergence, paralysis of upward gaze

86
Q

What are the signs of parinaud syndrome

A

Palsy in upgaze
Eyelid retraction
Pupillary light near dissociation
Convergence-retraction

87
Q

What is periodic alternating nystagmus

A

Rare horizontal
Congenital or acquired
The nystagmus changes every 90 seconds

Alternating head turnings to adapt
Can be fixed with surgery if congenital

88
Q

What are the hallmark sign of periodic alternating nystagmus

A

Shifting null point

89
Q

What can periodic alternating nystagmus be seen with

A

Degenerative process involving the cerebellum

Skew deviation

90
Q

What is voluntary nystagmus

A

Rapid with small amplitude and short duration
Pendular
Conjugate
Horizontal
Produced voluntarily by the patient
May run in families
Induced by convergence and there is oscillopsia
Only maintained for a few seconds because of fatigue
Can be part of a spasm of the near reflex

91
Q

What are the goals of nystagmus management

A

Improve VA, Ocular motor control, Binocularity, cosmesis, and comfort

92
Q

What is purpose of refractive correction in nystagmus

A

To improve the clarity of the retinal image to maintain stead fixation

To lessen the nystagmus

Should be considered as first treatment

93
Q

What Rx would you prescribe glasses for in nystagmus?

Hyperopia
Astigmatism
Myopia

A

Hyperopia: 1-2D
Astigmatism: 0.5D or more
Myopia: 0.5D or more

94
Q

What does plus adds do in nystagmus treatment

A

It is valuable for improved VA and clarity for near point demands

Aids in accommodation at near

95
Q

Why would you use minus adds in nystagmus glasses?

A

To induce convergence since nystagmus can decrease with convergence

You need to make sure that it will not interfere with their binocularity first though

96
Q

Why are prisms used in nystagmus

A

To improve binocularity and reduce nystagmus intensity

An improve strabismus, induce convergence, move the null point

97
Q

How can you induce convergence

A

Use a small amount of BO prism to stimulate fusional convergence and dampen the nystagmus

98
Q

How can prisms be used for anaomalous head postures

A

Yoked prisms can improve VA and slow down the nystagmus

Base is placed in the same direction as the head turn (keeps eyes in null point)

99
Q

What do yoked prisms do

A

Shift the image towards the null point

100
Q

Why would you use ground in prism instead of the Fresnel prism

A

If Fresnel is used for large prisms there can be a degradation to vision

Ground in vision does not prevent distortion in the vision

101
Q

How is the prism positioned for nystagmus with a head turn

A

APEx is placed towards the null point

Base is towards the turn

102
Q

What is the down side of occlusion in nystagmus

A

Can lead to latent component manifestation

103
Q

Why is amblyopia treatment in nystagmus patients difficult

A

Latent component can show up

Need to consider using plus lenses over better seeing eye (use enough to blur but not enough to disrupt fusion)

104
Q

Why is vision therapy used in nystagmus

A

For fusional vergences or to improve motor control and for suppression that could lead to manifest latent nystagmus

105
Q

When is pharmacological treatment used in nystagmus

A

When the nystagmus is due to a systemic problem

Oscillopsia, vertigo from vestibular nystagmus, downbeat nystagmus

Gabapentin can help reduce the severity f nystagmus (adverse effects)

106
Q

When is surgery used in nystagmus

A

For face turns, head tilts, chin elevation, or any anomalous head position

107
Q

What is the Kestenbaum technique

A

Commonly used to shift the null point closer to the primary position and eliminate the head turn

Nystagmus intensity is reduced, VA is improved, null point is wider

108
Q

What should you consider before doing surgery in nystagmus

A

Only for significant head turn (small turns are managed with yoked prisms)

Best when done in children older than 4yoa.

Have to reoperate in 50% of cases

109
Q

What is spontaneous vertical deviation

A

Spontaneous upward movement of one or both eyes when tired, fusion is broken, or inattentive

Found with infantile strabismus

110
Q

What is the presentation of dissociated vertical deviation

A

No symptoms
2-3 yoa
Hyperdeviation in one or both eyes (the other eye does not have hypo deviation)
Can be spontaneous(manifest) or when one eye is covered (latent)

Nystagmus can als be present

111
Q

How do you treat dissociated vertical deviation

A

Surgical treatment only if large or occurs frequently

Mostly no treatment
Difficult to measure

112
Q

What is inferior oblique overaction

A

The eye is elevated in ADDuction

Present in children with infantile strabismus
Bilateral or unilateral
Little or no deviation in primary
Found in 2/3 of children with congenital strabismus

Surgery only if large

113
Q

What is pattern strabismus

A

Present when a horizontal deviation changes in magnitude between up gaze and down-gaze

Vertical
Non-Comitant
In XT or ET
Cause is unknown

114
Q

What is V pattern

A

Horizontal deviation is more divergent in up-gaze than in down-gaze

115
Q

What is A pattern

A

Horizontal deviation is more divergent in down-gaze than in up-gaze

116
Q

How do you determine A/V pattern

A

Measure the alignment in primary at distance(with habitual) and then about 25 degrees from primary in up-age and down-gaze

117
Q

V pattern significance

A

Significant when difference between up-gaze and down-gaze is at least 15pd

Most common
Can be seen in infantile ET
In patients with SO palsies (is bilateral especially)

Pt may adopt a chin up compensatory head posture

118
Q

What is the significance of A pattern

A

Significant when difference between up-gaze and down-gaze is at least 10pd
There is more divergence inferior

Patients with XT
May have chin down head posture

Common in patients with infantile strabismus with craniofacial malformations, and Down’s syndrome

Motility (5 decks)

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