This document provides an overview of esotropia, including its types, causes, and clinical features. Esotropia is a convergent misalignment of the eyes. There are two main types - infantile esotropia, which presents in the first 6 months of life, and accommodative esotropia, which is usually caused by hyperopia. Accommodative esotropia can be fully, partially, or non-refractive. Clinical assessment of esotropia involves measuring visual acuity and the angle of deviation using tests such as cover-uncover and prism cover tests. Treatment involves correcting refractive errors with glasses and potentially strabismus surgery.

1. ESOTROPIA

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

4. ESOTROPIA
 Manifest deviation that is
not controlled by fusional
mechanism
 Constant deviation

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

8. FLAT, BROAD NASAL BRIDGE

10. PROMINENT EPICANTHAL FOLD
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

13. Large (>30 Δ) angle and stable.

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

16. DOLL'S HEAD MANUEVER: ABDUCTION DEMONSTRATION

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

21. Dissociated vertical deviation
(DVD)

22. Asymmetry of optokinetic nystagmus is present.

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.

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

29. Fully accommodative esotropia

30. Partially accommodative esotropia

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

34. Convergence excess

35. Convergence excess esotropia

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

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

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%

42. OCULOCARDIAC REFLEX

43. HISTORY TAKING
 Age of onset
 General Health condition
 Birth History
 Family History
 Symptoms
 Previous ocular history

44. ASSESSMENT OF STRABISMUS
 Visual acuity
 Full fundus examination
 Hirschberg
 Cover – uncover test
 Alternate cover – uncover test
 Krimsky’s Test
 Prism Cover Test

45. RETINOBLASTOMA

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

50. Stereopsis
 Perception of depth
 Examples
- Titmus Test
- TNO random dot test
- Frisby Test
- Lang Test

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

54. 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.

61. Krimsky’s Test

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

65. Prism Cover Test

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.