Abnormal Head Posture in squint

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Abnormal head posture

• Dr Madhu Karna
• Consultant Pediatric Ophthalmologist

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Normal head posture

• Eyes usually remain in frontal plane
• gaze away momentary - followed by prompt
  repositioning of the head to face the object of
  regard.

12 grams of force is
required (relatively little effort)
to maintain eyes in primary
position
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Maintaining gaze to one side with face straight
ahead, is tiring Natural tendency- rotate the
head, facing the object of regard
Gaze to the side- more tension on all
horizontally acting muscles holding the eyes in
position
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How do the eyes get to side gaze?
Oculocephalic
Saccade
Pursuit
During rapid refixation muscles contract up to
100 gm or more at peak velocity of 200 /sec.
The eyes track in a slow following movement
Influenced by middle ear static factors. Confirms
intact muscle/neural arc
Velocity depends on speed of moving object
followed, a few degrees per sec.
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Anomalous head posture

• To achieve comfortable vision - to avoid
  diplopia, to gain better vision in the case of
  nystagmus, find the null.
• Can occur in congenital ET and is always seen in
  spasmus nutans.

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Compensatory Head Posture for Diplopia The
head (face) moves where the eye(s) movement is
limited, for
VI N palsy-OD
Greater ET in right gaze, less in left gaze
To avoid diplopia the person turns his face
right, while the eyes assume levoversion. The
object of regard is straight ahead by egocentric
localization.
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Head posture in right superior oblique palsy
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Other Head Posture Strategies

Browns right eye - Face Up - Left
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Duane I syndrome (ET) limited abduction OD - Face
Right
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SR palsy or IR restriction one or both eyes
Chin Up Also "A" or V
Patient fusing in down gaze or may have null
nystagmus in down gaze
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IR palsy with limited depression one or
both eyes Chin Down also
with A or V pattern fusing in up gaze or null
nystagmus in up gaze
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Excyclo Torsion Down Gaze
Bilateral S.O. Palsy Chin Down
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An anomalous head posture to attain the null
point in horizontal nystagmus may reverse in
cases of periodic alternating nystagmus. The
period may be up to several minutes
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Thank you