This document discusses esotropia, which is an inward turning of one or both eyes. It defines esotropia and describes the different types including accommodative esotropia, congenital esotropia, and microtropia. It outlines the causes, characteristics, diagnosis, and management of each type of esotropia. Some key points covered include the role of accommodation and refractive error in accommodative esotropia, the importance of early treatment for congenital esotropia to prevent amblyopia, and the use of occlusion therapy, refractive correction, surgery, and botulinum toxin injection in the management of esotropia.

2.  Derived from 2 greek words- ‘eso’ which
means ‘inward and ‘trepo’ means ‘turn’.

3.  Apparent convergent squint
 Angle kappa- negative
 Causes:
 1. Telecanthus
 2. Epicanthus

7. (A)-Symmetric central
Asymmetric –
(B) - Pupillary margin: 15°
(C) - Close to limbus: 30°
(D) -Beyond limbus: 45°

8.  Three commonly recognized stages:
 Esophoria
 Intermittent Esotropia
 Esotropia

9. ESOPHORIA

10.  Esodeviation that is intermittently controlled
by fusion mechanisms.
 Manifest under certain conditions such as
fatigue, illness and stress.

11.  Esodeviation that is not controlled by
fusional mechanisms so that deviation is
constant

12. ESODEVIATION
INCOMITANT
PARALYTI
C
RESTRICTIVE SPASTIC
CONCOMITANT
ACCOMODATIVE
PARTIALLY
ACCOMODATIVE
NON
ACCOMODATIVE
•Neurogenic
•Myogenic
•Musculofacial
•other
Refractive
Non refractive
•Essential infantile
•Essential acquired
•Acute comitant
•Microtropia
•Cyclic esotropia
•Sensory esotropia
•Nystagmus blockage
syndrome

14.  Esodeviations due to excessive convergence
associated with accomodation are called
accomodative esotropia.
ACCOMODATIVE
ESOTROPIA
REFRACTIVE
NON
REFRACTIVE
PARTIALLY
ACCOMODATIVE

15.  MOST CONSISTENT FEATURE:
VARIABLE ANGLE OF ESODEVIATION
WHICH INCREASES WITH THE EFFORT
FOR ACCOMODATION

16.  Uncorrected hyperopia
 To see clear at distance- they accommodate-
esodeviation for distance fixation.
 Normal AC/A- therefore ET same for
distance and near (within 15 PD)
 NO CONVERGENCE EXCESS
 Respond well to full cycloplegic correction of
hyperopia

17.  Usually mild to moderate hyperopia (+2 to
+6D)
 Very high hyperopia- donot accommodate-
bilateral amblyopia
 Apart from ET and amblyopia, they may
present with asthenopia due to constant
accomodative effort.

18. 6/6 6/6

20.  Heterophoria method
 AC/A= IPD+ (∆n- ∆d)/3
 Normal- 5-7.5pd/1D
 Gradient method
 AC/A= N-D/3
 Normal- 3-5pd/1D

21.  ET for distance + convergence excess
(>15PD) ET for near (at 33cm)
 High AC/A ratio

22.  No clinically significant hyperopia
 No accomodation for distance- no ET for
distance
 High AC/A ratio
 >15PD ET for near
 ‘Hyper accomodative type’

23.  Weak accomodative mechanism
 Over-accomodation
 Normal AC/A ratio
 Convergence excess type
 Remote NPA and NPC- whereas hyper
accomodative type have a normal NPA
 Seen in early presbyopes or cases under
mild cycloplegia

24.  2nd year of life
 Variable angle of ET, presence of
convergence excess and full cycloplegic
error should be looked for.

25.  Full cycloplegic correction
 If convergence excess- bifocals are
prescribed.
 The minimal plus add that corrects
convergence excess ET is added.

26. Full cycloplegic
correction/bifocals
Residual esotropia
Non-accomodative
element
Partially accomodative- require
surgery for the non- accomodative
part
MR recession with or
without retro-equatorial
myopexy. (Faden)

27. 1. Early onset- high risk of amblyopia
2. Large angle ET(30pd)
3. Free alteration/ cross fixation in alternators
and fixation preference of normal eye in
amblyopes
4. No significant refractive error
5. No Neurologic deficit
6. Confirmed only after 4-6 months

29. 7.May be associated with:
 IOOA (68%)
 Nystagmus (33%)
 DVD(50%)
8. Asymmetric optokinetic nystagmus:
Temporal to nasal- smooth
Nasal to temporal- cogwheel

30. A special characteristic of congenital esotropia - OKN
asymmetry
Temporal to nasal (T/N)
Smooth, following and
rapid refixation
Nasal to temporal (N/T)
Jerky inaccurate
movements
with halting refixation
OKN asymmetry is present in all infants but becomes symmetrical by 6 months.
Patients with congenital ET retain OKN asymmetry

31.  Ciancia syndrome
 Lang’s syndrome

32.  Early onset ET
 Bilateral abduction limitation
 Manifest-latent jerk nystagmus (fast phase in
the direction of fixating eye)
- Increasing in abduction; decreasing in
adduction
- Face turn towards fixating eye
- Fixating eye in adduction(null point in
adduction)

33.  Early onset ET
 DVD
 Nystagmus
 Excyclodeviation of non fixating eye
 May be associated with torticollis

34. DIFFERENTIAL DIAGNOSIS
Cranial nerve 6th palsy Doll’s eye manouvere
Duane’s retraction syndrome Changes in palpebral aperture,
upshoot/downshoots on adduction
CNS anomalies Down’s syndrome, Mobius, Cerebral
Palsy, Albinism
Accomodative ET/ Partially accomodative
ET
Cycloplegic refraction
Nystagmus blockage syndrome Inverse relation between amplitude of
nystagmus and degree of esotropia

35.  Unknown
 Multifactorial
 Heritable factors- monozygotic twins
showing esotropia
 Developmental anomaly in first 4 months

36.  Depends on treatment of amblyopia
 Full cycloplegic refraction under atropine 1 %
eye ointment
 Full hyperopic correction
 Occlusion

37.  Conventional full time, fully opaque occlusion
of dominant eye.
 At no point during the treatment, is binocular
viewing allowed.
 Thus, patching is done for 3:1, 4:1 or 5:1
days for a 3,4 or a 5 year old child
respectively.
 Above 6 years, the regime remains 6:1 for all
ages.

38.  Vision assessment done monthly. (fortnightly
in infants).
 End point: free alternation of the two eyes
which is equally maintained.

39.  Large angle ET- earliest/ 4 months of age
 Small angle ET- proper hyperopic correction
till 6 months or till examination can be done
satisfactorily.

40.  Associated inferior oblique ‘v’ phenomenon
 Amblyopia therapy
 DVD
 Nystagmus
 Eccentric fixation or uncorrected amblyopia
have unpredictable results.

41.  MR surgery is more effective LR surgery
 Mono-ocular recession-resection or bimedial
recession
 MR 1mm surgery corrects 3-4.5 PD of
deviation
 LR 1mm surgery corrects 2-3 PD of
deviation

42.  Onset after infancy
 No accomodative factors and no neurological
cause (excluded by CT/MRI)
 ‘acquired essential (non-accomodative)
esotropia.
 Basic type or convergence excess type
 Rarely divergence insuffiency may be present.
 Management- Surgery with better binocular
visual potential than infantile esotropia

43.  Ultra small angle ET
 Missed by ordinary methods of examination
 Usually have amblyopia of one eye with
variable levels of binocularity
 1. Primary
2. Secondary(residual deviations after
surgery)

44.  Macular scotoma
 Good peripheral fusion with fusional
amplitudes and gross stereopsis

45.  Small angle (<5˚) heterotropia
 Harmonius ARC
 Mild amblyopia
 Partial stereopsis
 Based on fixation pattern Cover test
Type 1 Central fixation Shows tropia
Type 2 Eccentric fixation without
identity
Shows tropia
Type 3 Eccentric fixation with
identity
Does not pick up a tropia

46.  Type 3- eccentric fixation with identity implies
that angle of anomaly is same as the
eccentricity of fixation.

47. CONSISTENT
 Amblyopia
 ARC
 Relative scotoma on
fixation spot
 Normal or near normal
fusional amplitudes
 Defective stereoacuity
VARIABLE
 Size of deviation (5˚-8˚)
 Foveal or non-foveal
fixation
 Relationship between
degree of eccentric
fixation and angle of
anomaly
 Presence or absence of
anisometropia
 Positive or negative
cover test

48.  Macular scotoma by Bagolini’s glasses or
4PD test.
 Presence of amblyopia and associated
refractive error should be detected.

49.  Treat amblyopia with occlusion therapy
 Good prognosis if treated in younger
children.

50.  Sudden presentation
 c/o diplopia
 2 types:
1. Those which manifest after the fusion has been
interrupted by a patch or occlusion for a short
time.
2. Those which have no such interruptions to
fusion but have very poor fusional control,
which may be further compromised by physical
or emotional stress.

51.  First type- spontaneously resolve within 6
months.
 Second type- Surgery/ prismatic
neutralisation in case of small angle ET.

52.  Regular cycles of presentation
 Usually 24-48 hours of squint alternating with
same duration of no squint.
 Squint days:
 1. large angle ET (40-50PD)
 2. sensory anomalies
 3. squint is consistent.

53.  No squint days:
 1. BSV with good fusional amplitudes
 2. No latent squints
Lasts for a few months to years before they
become fully manifest squints
Surgery as per deviation on squinting days
gives satisfactory results.

54.  Infantile ET is associated with manifest-latent
and latent nystagmus.
 However, there is a special form of nystagmus
which has a dampening mechanism with eyes
in adduction
 Inverse relationship between ET and
nystagmus
 Nystagmus is present when eyes are straight
and it disappears when eyes are locked in ET.
 Management: Faden with or without B/L MR
recession.

55.  Lost vision in one eye usually develops
squint over a period of time.
 XT or ET depending on convergence tonus
 XT- in first year and after 8-9 years of age
 ET- after first year upto 8-9 years of age
 Refractive error and accomodative status of
the straight eye needs to be evaluated
before planning any cosmetic surgery

57.  Refraction and proper prescription including
use of bifocals
 Use of prisms
 Purpose:
 Fusion and binocular vision
 Maintains relationship between
accomodation and convergence
mechanisms

58.  PROPER CYCLOPLEGIA
 PROPER PRESCRIPTION- full cycloplegic
correction with no over or under correction.
 BIFOCALS- In case of high AC/A ratio

60.  Glass prisms- upto 7-8 pd over each eye
 Fresnel prisms- upto 25-30 pd

62.  Miotics
 Cyclopegics
 Chemodenervation by botox

63.  Site of action- ciliary muscles
 Facilitates accomodation
 Reduces accomodative effort
 Hence, reduces accomodative convergence

64.  Di-isopropyl-flourophosphate (DFP)
 Phospholine iodide (Echothiophate)- 0.03%,
0.06% and 0.125%
 Demecarium bromide (Humorsol)

65.  Desirable end results after use of miotics is
proper binocular alignment at all times,
especially near work with accomodative
tasks.

66.  To make patients accept full hyperopic
correction
 To suppress accomodative convergence
mechanisms and stimulate divergence

67.  This is still under trial by Scott and McNeer
 Infantile esotropes if aligned before 6 months
can have good functional binocularity.
 While the surgical effect of botox in adult eye
muscles is transient, effect in early infancy is
permanent because of the changes in the
developmentally immature muscles.

68.  Initial overcorrection may restructure the
ocular motility balance to yield better result
ultimately.
 However on the negative side, associated
changes of oblique overactions/ AVpatterns/
DVD may still require surgical correction.

69.  PRE OP EVALUATION
 Assessment of vision and amblyopia therapy
 Measurement of deviation

70.  Weakening
 Strengthening
 Aim- symmetrizing and not symmetric
surgery

71.  To split amount of surgery across two recti
rather than single large surgery in single
muscle alone
 If AV, with obliques overaction- vertical
shifting of horizontal recti or slanting
recession and resection can be done

72.  Recession
• Conventional
• Hangback
• Adjustable
• Vertical transposition of horizontal recti
• Slanting recession
 Retroequatorial myopexy

73.  Muscle is disinserted and reinserted to a
point closer to its origin.
 Induces a slack/laxity
 Muscle becomes less effective
 Reinsertion to be done within its arc of
contact
 Max recession defined by functional equator-
depends on arc of contact

74.  Max recession MR- 6mm LR- 8mm in adults
 Children- MR 5.5mm LR 7mm
 Minimum MR 3mm LR 4mm

75.  Recession is done with long ends of the
suture between the site of insertion and the
muscle.
 This is indicated if supramaximal recession
is intended and its difficult to pass sutures
that posteriorly
 Or, there’s a risk of scleral perforation in high
myopes

76.  Weakening effect is more than a
conventional recession because of a central
(mid width) sag.
 A pseudotendon may form in the intervening
space around the sutures which may lead to
a late under correction.

77.  Ability to modify the position of a newly operated
muscle by use of adjustable sutures.
 Indications:
 Large angle deviations where results may be
inconsistent
 Reoperations/ previously injured muscles
 Incomitant starbismus with diplopia when precise
post operative results are desired.
 Mechanical limitaions as in dysthyroid orbitopathy
or musculofacial anomalies.
 Aberrant innervation in III nerve palsy or DRS

78.  Posterior fixation suture
 Musle is sutures posterior to insertion farther
than its limit of arc of contact.
 This shortens the lever arm and reduces the
action of muscle in its field of action.
 No change in primary position if no recession
is done along with Faden.

79.  MR- 12-14mm
 LR-16-20mm
 SR- 14-16mm
 IR- 14-16mm
 More effective on MR; least on LR

80.  Non accomodative convergence excess
esotropia (MR)
 Nystagmus blockage syndrome (MR)
 DVD (SR)
 Paralytic strabismus (contralateral synergist)
 DRS (contralateral MR)
 Additional weakening effect over recessed
muscle.

81.  Resection
 Advancement
 Transpositioning of adjacent muscles

82.  Shortens muscle length making itmore taut
 Improves efficiency by raising it to a higher
length tension curve
 Excision of tendinous part of the muscle.
 Therefore max limit for
 MR- 6mm
 LR- 4.5mm

83.  Strengthening procedure whereby muscle is
reinserted closer to limbus.
 Reverse of recession
 Indications:
 To correct consecutive squint in a recessed
muscle
 In paralytic squint, in addition to resection.

84.  Classification and management of esotropia in
children.
 What is faden operation.
 Accomodative squint- signs symptoms
investigations
 Management of accommodative esotropia.
 Investigations and management of concomitant
esotropia
 Describe the clinical features and management of
partially accommodative esotropia

85.  Management of alternating convesrgent
squint
 Monofixation syndrome
 What is microtropia? Discuss the types and
clinical features of microtropia
 What are the features and differential
diagnosis of infantile esotropia? When it
should be operated and its prognosis for
binocular single vision (BSV)?

86.  *Define essential infantile esotropia? Give at
least four differential diagnosis of essential
infantile esotropia and give at least two
differentiating features among them. 2+8
 25. Describe Faden’s operation as applied in
management of strabismus.
 *Describe the Clinical Features, investigations,
indications and surgical management of
infantile esotropia, and its post-operative
complications.

87.  Classify and give complete management of
esotropias in detail
 Define and classify esotropia. Management of a
6 year old patient with esotropia
 Classify esotropia. How wouldyou plan the
management of convergneceexcess esotropia
in a 5 year old child? Describe the choice of
procedure and surgical planning in detail.