2. Outline
Introduction
Type
Pseudoexotropia
Classification
Important subtypes
Infantile esotropia
Accomodative esotropia
Other types of esotropia
3. Introduction
An esodeviation is a latent or manifest convergent
misalignment of the visual axes.
Esotropia is the most common, >50 % of ocular
deviations in the pediatrics population
Important causes of ET
- Infantile ET
- Accomodative ET
6. Type
Comitant strabismus
Degree of misalignment/ Angle of
deviation is the same in all fields of gaze
Variability of angle is within 5Δ
Incomitant strabismus
Degree of misalignment/ Angle of
deviation varies in all fields of gaze
Result of abnormal innervation or paralysis
7. Pseudoesotropia
False appearance of esotropia when the visual
axes are actually aligned.
The appearance may be caused by
a flat, broad nasal bridge
prominent epicanthal folds
a narrow interpupillary distance
11. Infantile (Congenital) Esotropia/
Early-onset esotropia
The first 6 months of life
no significant refractive error
no limitation of ocular movements.
Variable, transient, intermittent strabismus in first 2–3 months of
life.
If an esotropia is present after age 2 months, is constant, and
measures 30 prism diopters (Δ) or more
12. Clinical features
Large (>30 Δ) angle and stable.
Alternating fixation in the primary position
Cross Fixation
Normal refractive error (therefore not accommodative
ET)
Need to exclude VI CN palsy (cover one eye, elicit
Doll’s reflex)
Latent nystagmus
Poor potential for BSV
14. Alternating fixation in primary position
• Right eye fixates there is a left
esotropia.
• Left eye fixates a right esotropia is
present.
• Equal vision in each eye (no
fixation preference).
15. Cross-fixating in side gaze
uses the left eye in right gaze
uses the right eye on left gaze
a false impression of bilateral abduction
deficits
17. Signs ( continuation)
Nystagmus is usually horizontal.
Latent nystagmus (LN) is seen only when one eye is covered and the
fast phase beats towards the side of the fixing eye.
18. Signs (continuation)
Inferior oblique overaction
Dissociated vertical deviation (DVD) develops in 80%
by the age of 3 years
Asymmetry of optokinetic nystagmus is present.
19. Inferior oblique overaction
may develop commonly at age 2 years .
becomes bilateral within 6 months
Inferior oblique weakening procedures include
disinsertion, recession and myectomy.
20. B/L inferior oblique overaction
(A) Straight eyes in the primary position;
(B) left inferior oblique overaction on right
gaze;
(C) right inferior oblique overaction on left
gaze
23. DIFFERENTIAL DIAGNOSIS
Congenital b/l 6th n. palsy
Abduction deficit and esotropia of the affected eye
Duane syndrome type
Limited abduction with small-angle esotropia in
primary gaze, abnormal face turn, and incomitance.
Palpebral fissure narrowing of the affected eye on
adduction.
24.
25. Medial wall fracture
A history of trauma
Anomalous head posture and incomitance.
Forced duction testing needed
Nystagmus blockage syndrome
Manifest nystagmus and be orthotropic when inattentive
Variable esotropia and mild nystagmus when attentive.
26. Mobius syndrome
congenital
non-progressive uni- or
bilateral paralysis of the
facial musculature and full
preservation of the vertical
eye movements.
The main nerves affected
are the sixth (CN VI) and
the seventh (CN VII) which
results in abnormal gazing
and mask like facies
27. Prognosis
Patients with infantile esotropia frequently have good
vision despite reduced binocularity.
Earlier surgery is associated with improved
binocularity.
Treatment of amblyopia, along with multiple surgeries,
may be required to achieve the best visual and
binocular outcomes.
28. Accommodative esotropia
Refractive accomodative esotropia
AC/A ratio is normal
Physiological response to excessive hypermetropia, ( +2.00 and +7.00 D.)
Typically presents at the age of 18 months to 3 years (range 6 months to 7 years)
Fully accommodative esotropia
Hypermetropia with esotropia when the refractive error is uncorrected
Following optical correction of hypermetropia
Deviation is eliminated
BSV is present at all distances
Partially accommodative esotropia
Following optical correction of hypermetropia
Deviation is reduced, but not eliminated
Amblyopia is frequent
31. Non-refractive accommodative esotropia
AC/A ratio is high so that a unit increase of
accommodation is accompanied by a disproportionately
large increase in convergence.
Occurs independently of refractive error
2 type
Hypoaccommodative convergence excess
Convergence excess
32. Hypoaccommodative
convergence excess
High AC/A ratio
Due to decreased accommodation
(Accommodation is weak, necessitating increased
effort, which produces over-convergence)
Straight eyes with BSV for distance.
Esotropia for near, usually with suppression.
33. Convergence excess
High AC/A ratio due to increased accommodative
convergence
(Accommodation is normal, convergence is increased).
Straight eyes with BSV for distance .
Esotropia for near, usually with suppression
Straight eyes through bifocals
36. AC/A Ratio calculation
Accomodative Converegence
Degree of convergence induced by accommodation
AC/A Ratio
Accommodative convergence to accomodance ratio
Total acc.conv induced by each dioptre of accommodation
AC/A expressed in Δ/D
Normal AC/A : 3-5 Δ:D
37.
38. Treatment
1. Correction of refractive error is the initial treatment.
Under the age of 6 years, the full cycloplegic refraction
After the age of 8 years, refraction should be performed
without cycloplegia
For convergence excess and hypoaccommodative esotropia
bifocals are used
2. Surgery
Only if spectacles do not fully correct the deviation and after
every attempt has been made to treat amblyopia.
Bilateral medial rectus recessions
Unilateral medial rectus recession combined with lateral
rectus resection
39. Surgical therapy options
Stage surgery
Recession of both medial rectus, then
+/- LR Resection
IO Overaction correction
Unilateral medial rectus recession
with lateral rectus resection -
preferred if there is amblyopia or an
anatomic defect of one eye
An acceptable goal is alignment of the
eyes to within 10 Δ
Timing of surgery
Done before two years of age
results in better binocular vision and
stereopsis
40.
41. Complications of treatment
Undercorrection
Overcorrection – rare
Surgical complications
Uncommon
Oculocardiac reflex : 14 – 19 %
Scleral perforation : 0.3 – 7.85 %
Retinal detachment following globe perforation is rare, with a rate of
approximately 1/25,000.
Cellulitis - 1/2000 cases.
Endophthalmitis- 1/18,500 TO 1/350,000cases
Anterior segment ischemia 1/13,000 cases.
Lost rectus muscle has been reported as 1/5000 cases, and the incidence of
Slipped rectus muscle 1/1300
Reoperation rates
25% to 69%
46. Visual Acuity
Preverbal children –
Verbal children
- 2 years : crowded Kay pictures
- 3 years : matching of letter optotypes ( keeler
logMAR )/ Cardiff acuity Test
- older children: Snellen
47.
48.
49.
50. Stereopsis
Perception of depth
Examples
- Titmus Test
- TNO random dot test
- Frisby Test
- Lang Test
51.
52.
53. Tests for sensory anomalies
Worth Four-dot Test
This is a dissociation test that can be used with both
distance and near fixation and differentiates between
BSV, ARC and suppression.
Bagolini striated glasses
4 Δ prism test
Worth Four-dot Test
55. Hirschberg’s Test
• Abnormal reflex:
• Border of pupil (15° or 30 prism
D)
• In between border and limbus
(30° or 60 prism D)
• Limbus (45° or 90 prism D)
• 1 degree = 2 prism dioptre
56. Cover Tests
1. Cover-uncover test:
• Cover component:
• Detects heterotropias
• Cover straight eye
• Look at uncovered deviated eye (movement indicates
tropia)
• Uncover component:
• Detects heterophorias
• Uncover straight eye
• Look at uncovered eye for deviation and refixation
(movement indicates phoria in this eye)
57. Possible results of the cover test. (A) With the right eye fixing, no
movement indicates orthotropia or (B) left exotropia; (C) with the
left eye fixing, abduction of the right eye indicates esotropia
58. Possible results of the uncover test. (A) No movement indicates
orthophoria; (B) adduction indicates exophoria; (C) abduction
indicates esophoria
59. 2. Alternate cover-uncover test:
• Detects heterophorias
• Alternate cover and uncover both eyes
• Look at uncovered eye for movement (movement
indicates phoria in that eye)
60. Krimsky’s test
The Krimsky test involves placement of prisms in front of
the deviating eye until the corneal light reflections are
symmetrical.
64. Prism Cover Test
measures the angle of deviation
includes the alternate cover test with prisms
Prisms of increasing strength are placed in front of one
eye with the base opposite the direction of the
deviation
The end-point is approached when no movement is
seen.
To ensure the maximum angle is found, the prism
strength can be increased the point of reversal
Post op diplopia test can be done to determine the risk
of potential diplopia
66. Take Home Message
Rule out pseudoesotropia!
Rule out retinoblastoma
Earlier surgery is associated with
improved binocularity for early onset
esotropia
Treatment of amblyopia, along with
multiple surgeries, may be required to
achieve the best visual and binocular
outcomes.
Editor's Notes
Manifest or latent: manifest squint is present when the eyes are open and being used, whereas in latent squint the eye turns only when it is covered or shut.
Optokinetic nystagmus (OKN) is nystagmus that occurs in response to a rotation movement. It is present normally.
AC/A ratio;The measurement of the convergence induced by accommodation per diopter of accommodation
To determine the change in accommodative convergence that occurs when the patient accommodates or relaxes accommodates a given amount
Abnormalities of the AC/A ratio are an important cause of certain types of esotropia
Recession of the medial rectus is a measured retroplacement of the muscle from its original insertion.
Resection involves detaching one of the eye muscles, removing a portion of the muscle from the distal end of the muscle and reattaching the muscle to the eye.
