Non- Accommodative Convergent Squint
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Transcript of Non- Accommodative Convergent Squint
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Definition
Non-Accommodative Esotropia or Non-Accommodative convergent Squint refers to the ESO-DEVIATIONS which are not primarily elicited by the direct influence of ACCOMMODATION.
Characterized by-Comitant Esotropia
-Acquired
-Onset after 6 months to 5 years
-Small to large angle deviation
-little or no hyperopia
-Normal AC/A ratio
-No neurologic or systemic sign or symptoms
SQUINT
Pseudo Squint
Manifest Squint (Tropia)
Latent Squint (Phoria)
Horizontal
Vertical
Cyclo
-Eso
-Exo
Comitant
Incomitant
Secondary
Accommodative
Non-Accommodative
Microtropia
Nystagmus Blockage Syndrome
Non-Accommodative Esotropia
Essential
Infantile Acquired
Basictype
ConvergenceExcess
DivergenceInsufficiency
Acute acquiredComitant eso
Acute strabismus afterArtificial interruptionof fusion
Acute strabismus Without Precedingdisruption Of fusion
Acute esotropiaof neurologic origin
Cyclic
Recurrent
A. Essential B. Acute Acquired Comitant
A. 1.ESSENTIAL INFANTILE ESOTROPIA
-Esotropia unilateral or bilateral
-occurs after birth within 6 months
Etiology
-Primary cause idiopathic
-Secondary causes are :
>Primary motor dysfunction associated with poor fusion
>family history of strabismus
>born prematurely
>a seizure disorder of hydrocephalus
FIXATION PATTERN INVESTIGATION
. Doll’s eye movement
. Alternate Patching
ASSOCIATED FACTOTS
Nystagmus; both manifest (rare) and latent (common)
Amblyopia ; not common
Inferior oblique Over Action
Abnormal Head Posture
DVD OR DHD
Asymmetric Optokinetic Nystagmus
Placing object on lateral side
Clinical Features Amount of Deviation =30- 40
Onset = after birth – 6 months (75% 2-3 months)
Fixation Pattern = cross fixation
Visual Acuity = Normal or Equal in Both Eyes
Refractive Error = may or may not present
TREATMENT Muscle Surgery – first check for associated factors and then wait for 6- 7 months for
surgery
Bilateral MR Recession or LR Resection
A. 2. ESSENTIAL Acquired Esotropia
a. Basic
b. Convergence
c. Divergence Insufficiency
a. Basic Esotropia
- Comitant Esotropia
- Amount of deviation is almost equal for distance and near in optically corrected eye
- Normal AC/A ratio
Etiology
-Innervational imbalance in muscle Excessive Tonic convergence
Muscle Imbalance
Improper Muscle Tone
CLINICAL FEATURES
Onset = after 6 months – 5 years
Amount of Deviation = almost equal for distance and near
Normal AC/A ratio
NPA within normal limit
Refractive Error = Hyperopia or Emmetropia
TREATMENT
(No glasses or miotics are helpful)
-First treat amblyopia
-Muscle Surgery (BL MR recession but depends on surgeon)
b. Convergence Excess Esotropia
- Comitant Esotropia
- More deviation at near than distance
-Divergence is normal ( Deviation at distance is neutralized)
-Not associated with any refractive error or High AC/A ratio
Etiology
Increased Innervational Tone of Converging Muscle
Clinical Features
onset – 1 to 5 years of age
AC/A ratio is normal
NPA is normal
Amount of Deviation is more at near than distance
Refractive Error may be Hyperopic or else EMMETROPIC
TREATMENT
Muscle Surgery ( BL MR Recession but depends on surgeon)
C. DIVERGENCE INSUFFICIENCY ESOTROPIA
Comitant esotropia in which deviation is more in distance than near and is associated with the weakening of the diverging muscle.
- Convergence for near is normal
- Chances of amblyopia is high
Etiology
Innervational imbalance in muscle action
Clinical Features
- After 6 months to any age
- AC/A ratio is normal
- NPA is normal
- Amount of deviation is more at distance than near
- Refractive Error is not associated
TREATMENT
Muscle Surgery is not reliable
Spectacles with BO prisms are helpful
Spectacle to be worn when distance vision is needed
B. ACUTE ACQUIRED COMITANT ESOTROPIA
Comitant esotropia which is always associated with diplopia.
It has acute onset and so can occur at any age.
It is not associated with paralysis of muscle
B.1. ACUTE STRABISMUS AFTER ARTIFICIAL INTERRUPTION OF FUSION
Patients may have no history of Squint.
Esotropia occurs after interruption of FUSION.
Fusion breakdown conditions are :-
i. Prolonged bandaging or Patching
ii. Occlusion in refractive amblyopia
iii. Swelling of eyelid followed by trauma
Postulate ; initially patients have ESOPHORIA which was being controlled
by well self functioning fusion.
CLINICAL FEATURES
Onset is acute , can occur at any age group
Diplopia is always present
Amount of Deviation is slightly more in near than distance
Associated with precipitating factors
TREATMENT
Refractive Error management
Systemic Illness management
Muscle Surgery
STRATEGY
Patient may close one or both eye to avoid diplopia
Refractive Error or Systemic Illness
BL MR Recession or BL LR Resection
Removal of Precipitating factors may dissolve deviation in some cases.Unless, Surgery is done
B.2. ACUTE STRABISMUS WITHOUT PRECEEDING DISRUPTION OF FUSION
Characteristics:
Acute onset
Diplopia
Relatively large angle of Esotropia
No sign of paralysis of muscle
No interruption in fusion is associated
Precipitating Factors
CLINICAL FEATURES
Onset is acute for all age group
Refractive error has minimal effect
Accommodative Element is minimal
Amount of deviation ranges from 20 - 60
Prolonged illness
ETIOLOGY
Idiopathic
TREATMENT
Refractive Error management
Systemic Illness management
Muscle Surgery BL MR Recession or BL LR Resection
STRATEGY
Removal of Precipitating factors may dissolve deviation in some cases.
Unless, Surgery is done
B.3. ACUTE ESOTROPIA OF NEUROLOGIC ORIGIN
Characterized by
It is always associated with neurological problems like
CLINICAL FEATURES
Etiology neurologic origin
Onset is acute
Refractive error Influence is minimal
No certain associations, sign or symptoms
Hydrocephalus
Brain Tumor
Craniocervical junction anomaly
TREATMENT
STRATEGYBeing a life threatening entity
Refer
To Neurologist
Treatment may dissolve Esotropia
If Not
Go for Surgery
C. CYCLIC ESOTROPIA
Characterized by
o A strabismic and no- strabismic phase of 24 hours each.
o This 48 hours of cycle is most common.
o However 72 and 96 hours cycle is also reported.
o Cycle may last from 4 months to several years.
o Unless treated , esotropia becomes constant.
CLINIAL FEATURES
Onset – early infancy
Amount of Deviation for both Near and Distance ranges from 40-70
Suppression in one eye
History of Amblyopia after being constant deviation
Fusional Amplitude is defective or absent
Fusion and stereopsis are normal
No manifest deviation, esophoria may be present.
Usually during early childhood
Non strabismic phase
Not related to
Visual Acuity
General or Ocular fatigue
Accommodation
Disruption of sensory fusion
Esotropia may be UL or B L
ETIOLOGY
Idiopathic
TREATMENT
Muscle Surgery
D. RECURRENT ESOTROPIA ( AKA Malignant Esotropia)
An unusual form of esotropia which reoccurs of the same angle even after multiple
operations.
No associations with conditions like :-
Increased uncorrected hyperopia
A deep seated ARC
Nystagmus blockage syndrome
An unstable AC/A ratio
Blind Spot Syndrome
CLINICAL FEATURES
Recurrent occurrence
AC/A Normal
Refractive Error influence is minimal
ETIOLOGY
Idiopathic
TREATMENT
Initially Muscle Surgery
BI Prisms mounted on spectacle