Abnormal Head Posture in squint

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Dr Madhu Karna Consultant Pediatric Ophthalmologist

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Abnormal head posture:

Abnormal head posture Dr Madhu Karna Consultant Pediatric Ophthalmologist

Normal head posture:

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

Slide3:

Maintaining gaze to one side with face straight ahead, is tiring Natural tendency- rotate the head, facing the object of regard Gaze to one side Gaze to the side- more tension on all horizontally acting muscles holding the eyes in position

Slide4:

How do the eyes get to side gaze? Saccade During rapid refixation muscles contract up to 100° gm or more at peak velocity of 200 /sec. Velocity depends on speed of moving object followed, a few degrees per sec. Pursuit The eyes track in a slow following movement Oculocephalic Influenced by middle ear static factors. Confirms intact muscle/neural arc A few degrees/sec. Depends on head movement Eye muscles are under more tension in gaze away from primary

Anomalous head posture:

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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The chin is down and the head tilted left while the eyes look up to the right. This compensates for both the vertical and the torsional defect. Head posture in right superior oblique palsy

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Other Head Posture Strategies Brown’s 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

Slide11:

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

Slide13:

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

Slide14:

In cases of restricted movement of the eye (s) from mechanical restriction or muscle weakness, resulting in diplopia, think of the head as the eyeball . The head moves where the eye cannot. The eyes then move opposite the head (face) direction to avoid the direction of limited movement thereby avoiding diplopia

Thank you:

Thank you