Lecture 7-8 Esotropia investigation and Management

Question 1

What are the classifications of esotropia?

Answer 1

PRIMARY. CONSECUTIVE. SECONDARY
constant:
accommodative- with an accommodative effort

non-accommodative: infantile, nystagmus blockage, without an accommodative element, late onset

intermittent:
related to time-cyclic

related to distance- Near, Distance

related to accommodative effort- fully accommodative, convergence excess

Question 2

What is consecutive esotropia?
What is primary esotropia?
What is secondary esotropia?

Answer 2

-was previously XOT
-unplanned overcorrection of XOT or purposely planned to protect from post-operative drift
-over liberal surgery (surgeon has accidentally done it)

-primary problem was SOT

-1st thing to happen to px is pathology (e.g., corneal opacity, macular lesion, glaucoma, optic atrophy, retinoblastoma)
-vision loss in eye with pathology. px cant fuse blurred images and clear image.

Question 3

If px develops pathology immediately after birth, what secondary tropia are they likely to get?

If px develops pathology as a young child, what secondary tropia are they likely to get?

If px develops pathology as an older child/adults, what secondary tropia are they likely to get?

Answer 3

• SOT or XOT

-SOT due to lots of accommodation

-XOT due to less accommodation

Question 4

What is the difference between a constant and intermittent tropia?

Answer 4

*Constant: on cover test there will be a tropia everywhere
*Intermittent: phoria in some places

Question 5

CONSTANT ESOTROPIA WITH AN ACCOMMODATIVE ELEMENT

what are its features?
what is a likely outcome?
what makes it worse?
what is it associated with?
What is the management?

Answer 5

-Angle of tropia will be greater at near than distance

-unilateral amblyopia

-accommodating. if they take hyperopic specs off, they need to accommodate so without glasses eso will be worse.

-hyperopia

*Cycloplegic refraction, fully correct hypermetropia
*Leave correction if cosmesis is good and symptom-free
*Treat amblyopia
*If angle is still unsightly Refer for surgery/BTXA to:
-restore BSV if there is potential
-restore to improve appearance
-choice of surgery depends on near and distance measurement

Question 6

INFANTILE ESOTROPIA

when does it occur?
what are these children likely to have?
what are the features?
Are they likely to have amblyopia?
What is the management?

Answer 6

3-4 months. onset of SOT before 6 months.

other neurological and developmental problems

-cross fixation
-Angle greater than 30
-usually alternating eso
–may have small vertical deviation
-Dissociated vertical divergence DVD
-Manifest Latent nystagmus
-IO overaction in OM
-CHP
-Asymmetry on OKN (nasal to temporal will be weak)
-very unlikely to have any binocular vision
-Supression responses on BV tests

alternation often prevents amblyopia
without surgery they can get constant unilateral eso with amblyopia

*Cycloplegic refraction
*Amblyopia treatment
*Surgery aims:
-improve cosmesis (restorative/reconstructive surgery)
-restore reduced form of BSV
-Refer before 2 years old

Question 7

What is dissociated vertical divergence?

Answer 7

*presents before 2 years
-Eye drifts upwards spontaneously or after being covered
*Eye drifts up (variable elevation) and extorts.
*As eye elevates and extorts, it intorts as it depresses.
*Can use Spielman occlude to see the deviation
*Usually bilateral, often asymmetric

Question 8

NYSTAGMUS BLOCKAGE SYNDROME

what causes this type of esotropia?
what are the features?
What is the management?

Answer 8

develop an eso trying to stop the nystagmus

-congenital, horizontal manifest nystagmus
-CHP towards fixing eye
-SOT is variable in angle
-nystagmus is the same when one eye is covered or both eyes are open
- amplitude of nystagmus increases on abduction
-As SOT increases, nystagmus amplitude decreases

referral

Question 9

WITHOUT AN ACCOMMODATIVE ELEMENT ESOTROPIA

when is the onset?
what are the features?
What is the management?

Answer 9

after 6 months to 2 years

-refractive error is insignificant to angle
-near deviation=distance deviation
-amblyopia is common
-poor potential for BSV

*Prescribe rx for vision
*Treat amblyopia
*Refer if either symptomatic or worried about cosmesis for surgery/BTXA

Question 10

LATE ONSET ESOTROPIA

what is the onset?
what are the features?
what is the management?

Answer 10

between 2-8+ years. usually after 4/5 years old.

-may have been intermittent originally
-Diplopia usually present early stages rapidly moves to suppression.
- Older children more likely to experience diplopia
*Normal retinal correspondence and sensory and motor fusion present
*Correction refractive error no effect
-As they have NRC, there is potential to restore BSV
*Non accommodative so glasses don’t help SOT

*Might be associated with a brain tumour
*REFER THEM IN
-any sign of neuroglial problems, papilloedema, motility problems, nystagmus REFER
-surgery, BXTA

Question 11

FULLY ACCOMMODATIVE ESOTROPIA

When is the onset?
What is the etiology?
What are the symptoms?
what are cover test and BV results likely to be?
What is the management?

Answer 11

2-5 years old

moderate amount of uncorrected hyperopia (+3.00DS to +6.00DS)
-over +6.00: to large for child to attempt accommodating. They accept the blur.

SOT larger when tired or unwell

-with full rx: well controlled
-without specs: esotropia (unilateral or alternating)
good BV with rx

*Cycloplegic 1% or atropine refraction
*Prescribe full correction
*Do not adjust prescription to account for cyclo drops
*Full time glasses wear
*Parents may comment control is worse when they take specs off
*Prognosis excellent
*Yearly refractions
*Amblyopia rare
*Explain to parent child is focusing really hard to see which is causing the eye turn

If small hyperopic prescription of less than +3.00DS and cyl less than 1D:
* Exercises
Mist/clear technique
Lift up glasses
*child now accommodates to see clearly without glasses, this will also cause then to converge therefore cause an SOT & diplopia.
*Ask 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

*Teach social control if more than +3.00DS by “misty and clear”
*Surgery is NEVER indicated
*Can be managed by optometrist

Question 12

CONVERGENCE EXCESS ESOTROPIA

What is the etiology?
What are cover tests likely to be?
What is the management?

Answer 12

*High AC/A ratio
*Usually 8:1
*Every time they accommodate, they converge too much
*Usually, hyperopic.
* occasionally has emmetropia and rarely myopia
-usually equal VA

*SOT at near with accommodative target (will accommodate)-will find eso
*SOP & BSV at near with light (no accommodation)
*SOP & BSV at distance
*Without hyperopic Rx: SOT in all distances as they need to accommodate.

*Cycloplegic refraction: correct fully if hypermetropic. Under-correct if myopic.
*Treat amblyopia
*Achieve control of deviation. We want them to turn into a fully accommodative SOT
Need to give an ADD to stop them accommodating which will stop excessive convergence.

Bifocals
*Minimum near addition for reading to make eliminate SOT maximum you can give is +3.00DS
*achieve good BSV (BCA of 6/6 with reduced Snellen, good PFR)
*Amount of near addition then reduced by +0.50DS every 6 months
*Aim to leave straight (achieve BSV) with single vision lens

Contra-indication of bifocals: large deviation and high level of AC/A (more than 10:1). Consider surgery in these px. May need bifocals post-operatively.

Consider bifocals in those who are:
* Unwilling for surgery
* Distance SOP is small
* Age of child is enough to use bifocals correctly

Question 13

NEAR ESOTROPIA

what is the etiology?
what cover test results and features will you find?
what is the management?

Answer 13

*NEAR

*SOT at near
*SOP & BSV at distance
*Often nil significant refractive error-no glasses
*Normal AC/A
*Normal ocular motility
*Often have equal V-A

refer to HES for surgery

Question 14

DISTANCE ESOTROPIA

what types can you get?
what is the management?

Answer 14

WITHOUT MYOPIA
*Most patients’ elderly
*SOP & BSV at near
*Intermittent SOT initially at distance- can become more constant with time

WITH MYOPIA
moderate: 6-15 D, eye movements remain full
high: more than 15D, abduction restricted
*Progressive esotropia. Starts in distance and then becomes constant
*Restricted abduction and elevation (high myopia)
*Exclude VI nerve palsy

refer to HES for surgery
prisms

Question 15

CYCLIC ESOTROPIA

what are the features?
what is the management?

Answer 15

*RARE
*One day straight with BSV one day manifest SOT
*no binocular functions
*Often 48 Hours to complete the cycle
*Frequency of the manifest day often increases until becomes constant

*Need to give a diary to monitor
-refer to HES for surgery

Question 16

In what type of esotropia is amblyopia more common?

What are the different methods of measuring the angle of deviation?

what are you likely to find on ocular motility in a px with constant esotropia?

Answer 16

in constant esotropia

poor vision: KRIMSKY
best method: PCT
uncooperative: PRISM REFLECTION TEST
babies: HIRSCHERBERG TEST

SO u/a and IO o/a with a V pattern

Question 17

What is the controlled binocular acuity test?
Who should you do it on?

what results would you expect in someone with convergence excess SOT?

what results would you expect in someone with Near SOT?

what results would you expect in someone with fully accommodative SOT?

Answer 17

*Performed at near using the reduced Snellen/budgie stick
*Performed at distance using logMAR
*Get px to look at target and ask them to read down the chart
*When they say double as they read the chart, they become manifest. Will stop reading or not read as smoothly.
*Controlled binocular acuity is the line before they breakdown

All patients with intermittent esotropia where co-operation allows

manifest as the read down the chart at NEAR

wont get anywhere down the chart as manifest at near all the time

remains SOP all the way down the chart with rx

Question 18

What is binocular function like in somone
with constant esotropia?

What is binocular function like in someone with intermittent esotropia?

Answer 18

-ARC, diplopia, suppression

-normal sensory and motor fusion, stereopsis

Question 19

When is the post-operative diplopia test done?

How is the test carried out?

Answer 19

*px may have suppression but wants cosmetic surgery

*Measured with prisms
*Prism placed before deviated eye
*Base opposite the deviation then base in same direction
*Prism increased until patient notes diplopia
*Patients fixates on a light
*Can combine with red, green googles
*If complains of diplopia after small correction, then not a good candidate for surgery
*If px is moved all they way in without double vison: good candidate for surgery
*Can move them from an area where they are suppressed to an area they have double vision
*Risk of causing interactable diplopia

Question 20

What surgery is done to the eye muscles if the angle is larger at near?

What surgery is done to the eye muscles if the angle is larger at distance?

What surgery is done to the eye muscles if the angle is the same at near and distance?

Answer 20

both MR resections

both LR resections

MR and LR resection of one eye

Question 21

What is botulinum toxin A injection (BTXA)?
How does it work in esotropia?
What are its advantages?
When is it used?

Answer 21

*Neuro-toxin which paralyses muscle into which it is injected

*Injected into the medial rectus for esotropia
*Antagonist (lateral rectus) has the advantage
*Eye moves out

*Used when px is unfit for anaesthesia
*Very useful if post operative diplopia test suggests intractable diplopia as a possible outcome
*It is temporary, wears off after 12 weeks. So can be used if surgeon not sure of outcome

Used in:
-consecutive SOT: as already had surgery. Used when a lot of prev surgery done.
-residual SOT: reducing deviation might allow px to regain control
-secondary deviations: when vision is poor in one eye