Esotropia - investigation and managment - Miriam Flashcards

1
Q

what are the 3 main types of esotropia?

A

primary secondary and consecutive

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

what is a consectutive SOT?

A

previously XOT –> SOT

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

what is the most likely cause for consecutive SOT?

A

XOT surgery - left slightly exo to guard against post-operative drift towards XOT (commonly seen)

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

what is secondary SOT also called?

A

sensory SOT

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

what is a secondary SOT?

A

due to pathology (e.g. corneal opacity) and accommodation active therefore SOT

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

what is a constant SOT?

A

there is a tropia everywhere

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

what is an intermittent SOT?

A

SOT in some places, and phoria in some places

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

when does a constant SOT with an accommodative element decrease in size?

A

with hyperopic rx
in the distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a partially accommodative SOT?

A

after hyperopic correction, the tropia reduces in size but stays manifest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is partially accommodative SOT also known as?

A

constant SOT with accommodative element

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

is amblyopia common with a partially accommodative element?

A

YES - it is constant

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

when does infantile SOT occur?

A

before 6 months

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

what happens in infantile SOT? (in terms of vision)

A

cross fixation

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

what is cross fixation?

A

use of the right eye to view the left visual field and the use of the left eye to view the right visual field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is an approx size of infantile SOT?

A

30 D or more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

is amblyopia common in infantile SOT?

A

no UNTIL surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

why is amblyopia not common in infantile SOT until surgery?

A

usually an alternating SOT until surgery, then become constant unilateral with amblyopia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are 2 things you should look for in someone with infantile SOT?

A

DVD and MLN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is DVD and MLN?

A

dissociated vertical divergence
manifest latent nystagmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when does dissociated vertical divergence present?

A

before 2 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what happens with dissociated vertical divergence?

A

eye drifts upwards spontaneously (day dreaming like anisha)or after being covered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

which eye does a DVD occur in?

A

both but is asymmetric (therefore greater in one eye than the other)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

features of manifest latent nystagmus

A

amplitude increases on dissociaton and on aBduction
THEREFORE vision better on aDduction

clinically may not be able to see manifest component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what does the ‘manifest’ part of MLN mean?

A

nystagmus is present with both eyes open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what does the ‘latent’ part of MLN mean?

A

amplitude increased when eyes abducted outwards / or covered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

which way does the patient’s face turn to reduce nystagmus?

A

towards the fixing eye (to ADDUCT it) bc of cross fixation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

which way will the OKN response be weak? in infantile SOT

A

nasal to temporal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

in infantile SOT is there any binocular vision? why/why not?

A

UNLIKELY - due to manifest deviation so early on in child’s life unless very early surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what kind of responses will you find on BV tests in someone with infantile SOT?

A

suppression response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

in nystagmus blockage SOT, when does amplitude increase>

A

aBduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

in nystagmus blockage SOT, what happens when you cover one eye or both eyes?

A

nothing - it stays the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

why does someone develop nystagmus blockage SOT?

A

trying to stop the nystagmus as amplitude descreases on aDduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

is nystagmus blockage congenital or acquired?

A

congential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

is nystagmus blockage manifest or latent?

A

manifest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

when does non-accommodative SOT occur?

A

between 6 months and 2 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

is amblyopia common in non-accommodative SOT?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what happens when you use rx in non-accommodative SOT?

A

no change in size of the tropia - used to correct VA only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

does the deviation chnage in size at Distance or Near in a non-accommodative SOT

A

approx the same at both dist and near

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

when does late onset SOT occur?

A

between 2-8+ years old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what happens in early stages of late onset SOT?

A

may have been intermittent originally
diplopia –> suppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

do you get NRC or ARC in late onset SOT?

A

NRC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

do you have sensory and motor fusion in late onset SOT?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what happens when you use rx in late onset SOT?

A

no effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

when do you refer with a late onset SOT?

A

any sign of neuroglial problems, papilloedema, motility problems, nystagmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what is late onset SOT associated with ? (cause)

A

brain tumour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what is the aetiology of fully accommodative SOT?

A

uncorrected hyperopia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what is the approx amount of hyperopia in fully accommodative SOT?

A

+3.00 to +6.00

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

cover test results with a fully accommodative SOT?

A

without glasses = SOT (unilateral or alternating)
with glasses = SOP all distances with good recovery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

binocular functions in fully accommodative SOT?

A

good with rx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

onset of fully accommodative SOT?

A

2-5 years old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

does fuly accommodative SOT get worse at any point?

A

parents may report SOT larger when tired or unwell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

is amblyopia likely in fully accommodative SOT?

A

no unless anisometropia present too (unlikley)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

which type of SOT is usualy hyperopic but can be emmotropic?

A

convergence excess SOT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

what is the cause of convergence excess SOT?

A

high AC/A ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

cover test results with convergence excess SOT?

A

Near with accomm target = SOT
Near with light = SOP
Distance = SOP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what is the approx AC/A ratio in convergence excess SOT?

A

greater than 5:1 , could be as high as 15:1 (usually 8:1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

is amblyopia likely in convergence excess SOT?

A

only if uncorrected anisometropia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

cover test of near SOT

A

Near = SOT
Distance = SOP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

what is the likely refractive error in Near SOT?

A

nil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

what is the AC/A ratio in Near SOT?

A

normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

what is OM like in Near SOT?

A

normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

is amblyopia likely in Near SOT?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

who are the most likely patients with a distance SOT?

A

elderly or highly myopic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

cover test results of distance SOT?

A

Near = SOP
Distance = SOT

65
Q

How does a distance SOT start?

A

intermittent at distance and becomes more constant with time

66
Q

With high myopia, how does a distance SOT progress?

A

progressive - can become constant
can cause restricted abduction and elevation in extreme myopic cases

67
Q

with a distance SOT, which palsy do you need to exclude?

A

6th nerve palsy

68
Q

which SOT is the most rare?

A

cyclic SOT

69
Q

what happens with cyclic SOT?

A

constant on “squinting day” with no demonstrable binocular function

70
Q

what is the BSV like with a cyclic SOT on a “straight day”?

A

BSV with little or no SOP

71
Q

what questions to include in your H+S

A

which eye?
direction of strab
how often (constant/intermittent)
how long has it been there? (likelihood amblyopia)
when do parents notice (during a particular activity)
is their vision good?

Premature?
birth weight?
birth trauma?

any ocular pathology or treatment ? (secondary/consecutive)

GH - good? meds? allergies?
FH - strab? amb? refractive error?

72
Q

which 2 conditions are you more likely to have a manifest deviation?

A

Downs or cerebral palsy

73
Q

when is amblyopia common with SOT?

A

constant SOT (except if alternating)
or consecutive

74
Q

when is amblyopia uncommon with SOT?

A

intermittent SOT unless decompensated and untreated in childhood or anisometropia

75
Q

how is vision with secondary SOT?

A

poor

76
Q

why do a cover test to investigate SOT?

A

enables differentiation of different types of SOT
perform with and without rx
Near and distance
with a light and accommodative target at near if SOT
can look for DVD & MLN

77
Q

why do OM with SOT?

A

may find SO underactions and IO overactions with a V pattern esp in constant SOT

78
Q

why do NPC with SOT?

A

important indicator of control for near

79
Q

how do you measure the angle of SOT with poor vision?

A

krimsky

80
Q

how do you measure the angle of SOT (best method)?

A

PCT

81
Q

how do you measure the angle of SOT with uncooperative child?

A

Prism reflection test

82
Q

when should you use the hirschberg test?

A

babies

83
Q

what is CBA?

A

controlled binocular acuity

84
Q

who has CBA?

A

all px’s with intermittent SOT where cooperation allows

85
Q

how do you perform CBA?

A

at near using budgie stick
at distance using logMAR
line before they break down

86
Q

what is CBA in convergence excess SOT?

A

Near - SOT will occur as px accommodates to read further down the chart

87
Q

what is CBA in Near SOT?

A

Near SOT all the time not affected by accommodation

88
Q

what is CBA in fully accommodative SOT?

A

near with Rx - no SOT px remains SOP all the way down the chart, controlled when wearing glasses

89
Q

what is the best method to measure AC/A angle in convergence excess SOT?

A

gradient method using -3.00 lenses in both eyes and px fixes on 6/6 letter

90
Q

if px have ARC do you treat them? (constant SOT)

A

no

91
Q

how do you carry out the post-operative diplopia test?

A
  1. prism placed before deviated eye
  2. base opposite deviation , then base in same direction
  3. prism increased until px notes diplopia
  4. fixation target = light
    if double v quickly = bad candidate
    if no double = good candidate
92
Q

if a child is greater than 1 year, what % of cyclo do you use?

A

1%

93
Q

if a child is 6-12 months WITH LIGHT IRIS, what % of cyclo do you use?

A

0.5%

94
Q

if a child is 6-12 months WITH DARK IRIS, what % of cyclo do you use?

A

1%

95
Q

if a child is 3-6 months, what % of cyclo do you use?

A

0.5%

96
Q

how long do children need to wear glasses before accurate diagnosis?

A

1 month or longer

97
Q

what are the aims of investigation?

A
  1. diagnose type of strab and angle size
    2.does the px with constant SOT have the potential for BSV
    3.can you restore BSV in all positions of gaze
    4.record area of suppression (post-op dip test) and record density of suppression (amblyopia treatment)
98
Q

which SOT has the best visual prognosis?

A

fully accommodative SOT

99
Q

What is the likely clinical diagnosis?
Cover Test:
Near with Rx = slight RSOT
Distance with Rx = minimal RSOT
Near without Rx = moderate RSOT
Distance without Rx = small RSOT

A

constant with accommodative element

100
Q

what is the likely clinical diagnosis?
Cover test:
Near with accom target = RSOT
Near with light = slight SOP good recovery
Distant = slight SOP good recovery

A

convergence excess SOT

101
Q

what is the 1st stage of management?

A

IMPROVE VISION

102
Q

if referring child to hospital, do you prescribe?

A

yes - will be seen at hospital later

103
Q

what is the 2nd stage of management?

A

imporve alignment of visual axes

104
Q

what does stage 2 management include?

A

restore BSV
enhance ARC
if no potential for BSV - CONSIDER RESTORATIVE SURGERY (cosmesis)

105
Q

why do you not treat someone older than 5 for amblyopia?

A

could leave them with intractable diplopia - therefore use a sbisa bar before treating

106
Q

how much more likely are people with manifest stab to have depression?

A

10X

107
Q

why should you refer someone with a cosmetically large strab?

A

it affects their self-esteem, relationships, employment etc ..
WILL HAVE A CONSULTATION WITH DOC

108
Q

what are some conservative treatments for strab?

A
  • observe/monitor
  • optical (prisms or manipulating rx)
  • orthoptic excercises
109
Q

what are some non conservative treatments for strab?

A

surgery or botox

110
Q

why give a hyperopic glasses to treat?

A

relax accommodation and convergence
order FULL PLUS in all accommodative SOT

111
Q

which prisms do you give in SOT and why?

A

base out
resolves diplopa

112
Q

with late onset SOT what is important to measure before you do surgery?

A

binocular function with prisms

113
Q

which orthoptic exercises do you use for SOT?

A

improve negative relative convergence (CATS)

114
Q

when do you give orthoptic exercises?

A

intermittent SOT

115
Q

other than stereograms, what other orthoptic exercis can you use?

A

lend prism bar - BASE IN exercise

116
Q

what surgery needs to be done if the angle is larger at near?

A

medial rectus recessions

117
Q

what surgery needs to be done if the angle is larger in distance?

A

both lateral rectus resections

118
Q

what surgery needs to be doen if near angle = distance angle?

A

MR recession and LR resection in one eye

119
Q

what type of botox is used for SOT management?

A

BTXA (botulinum toxin type A injection)

120
Q

how does btxa work?

A

neuro-toxin which paralyses muscle into which it is injected, giving the antagonist the advantage

121
Q

when is it useful to use BTXA?

A

consecutive SOT
residual SOT
secondary deviations

122
Q

why is it useful to use BTXA in consecutive SOT?

A

already had surgery

123
Q

why is it useful to use BTXA in residual SOT?

A

reducing deviation might allow px’s to regain control

124
Q

why is it useful to use BTXA in secondary deviations?

A

when vision is poor in one eye

125
Q

what is an advantage of BTXA?

A

temporary results
useful to confirm if post-op diplopia test suggests intractable diplopia possible outcome
used when px is unfit for anaesthesia

126
Q

is consecutive SOT constant or intermittent?

A

can be either

127
Q

why does consecutive SOT occur?

A

surgical overcorrection of XOT

128
Q

when do you use an adjustable suture?

A

secondary SOT to fine tune the position of the eyes post-op in ADULTS

129
Q

why are patients left slightly SOT after surgery or BTXA (secondary SOT)?

A

to guard against consecutive XOT

130
Q

how do you manage a constant SOT with accommodative element?

A

FULLY correct hyperopia
treat amblyopia
refer for surgery/BTXA

131
Q

why do you refer for surgery/BTXA in constant SOT with accommodative element?

A
  1. restore BSV if there is potential
  2. Cosmesis restore to improve appearance
    (choice of surgery depends on near and distance measurement)
132
Q

how do you manage infantile SOT?

A

cycloplegic refraction
amblyopia treatment
surgery

133
Q

why do you refer for surgery in infantile SOT?

A

improve cosmesis
restore reduced form of BSV

134
Q

when should you refer someone with infantile SOT?

A

before 2 years old

135
Q

how do you manage constant SOT without accommodative element>

A
  • prescribe Rx for vision
  • treat amblyopia
  • refer is symptomatic or worried out cosmesis
136
Q

how do you manage nystagmus blockage SOT?

A

refer

137
Q

how do you manage constant late onset SOT?

A

Refer HES for surgery or BTXA

138
Q

what are the primary constant SOTs?

A

constant without accommodative element
constant with accommodative element
late onset
nsytagmus blockage
infantile SOT

139
Q

how do you manage fully accommodative SOT?

A

prescribe full correction - full time glasses wear
PARENTS MAY COMMENT CONTROL INITIALLY WORSEN INITIALLY

140
Q

recall with fully accommodative SOT

A

12 months

141
Q

is amblyopia likely in fully accommodative SOT?

A

rare

142
Q

what do you need to warn parents of with a fully accomm SOT

A

it will only get better with the glasses, otherwise they may think you made it worse

143
Q

if a small hyperopic rx, how do you treat fully accomm SOT?

A

exercises: MISTY/CLEAR or LIFT UP AND REPLACE GLASSES

144
Q

how does lift up and replace glasses work?

A

lift glasses up - child now accommodates to see clearly without glasses, this will also cause then to converge therefore cause an SOT & diplopia. Aske them to relax their accommodation and allow the image to become blurred and let them note that it is now single Then encourage them little bit by little bit to become clearer whilst maintaining a single image

145
Q

in a fully accommodative SOT, when do you indicate surgery?

A

NEVER

146
Q

who manages a fully accomm SOT?

A

optometrist

147
Q

how do you manage convergence excess SOT?

A
  • cyclo refraction
  • fully correct if hyperopic
  • under correct if myopic
  • treat amblyopia (monitor carefully)
  • achieve control of deviation to turn into fully accommodative SOT -BIFOCALS
148
Q

why do you give bifocals to convergence excess SOT?

A

stop them from accommodating so much, then turns them into fully accom SOT

149
Q

bifocals in convergence excess SOT?

A

minimum near add to eliminate sOT and have good BSV
amount of near add then reduced by +0.50 every 6 months
Aim to leave straight with single vision lens

150
Q

who would you consider giving a bifocal to when treating convergence excess SOT?

A
  1. those unwilling for surgery
  2. distance SOP is small
  3. child old enough to use correctly
151
Q

the maximum near add you can give to treat convergence excess?

A

+3.00

152
Q

what is a contra indication for using bifocals for convergence excess?

A

large deviation and AC/A greater than 10:1

153
Q

why could you give bifocals post-operatively?

A

still becoming SOT for near on accommodation

154
Q

how do we manage near SOT?

A

refer for HES surgery

155
Q

how do we manage distance SOT ?

A

prisms
refer for HES surgery

156
Q

how do we manage cyclic SOT?

A

refer HES for surgery

157
Q

convergence excess SOT will show..

A

esotropia on accommodation on near fixation

158
Q

bifocals can be used to treat..

A

convergence excess SOT

159
Q

adjustable sutures are particularly useful in which condition?

A

secondary SOT