Strabismus

Strabismus, also known as "heterotropia", "squint", "crossed eye", "wandering eye", or "wall eyed", is a disorder in which the eyes do not point in the same direction. It typically involves a lack of coordination between the extraocular muscles which prevents bringing the gaze of each eye to the same point in space, preventing proper binocular vision, which may adversely affect depth perception. The cause of strabismus can be a disorder in one or both of the eyes. For example nearsightness or farsightness. Making it impossible for the brain to fuse two images.

Types

Strabismus may be concomitant or incomitant.

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Concomitant strabismus means that the strabismus is equal regardless of which direction the gaze is targeted.

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This indicates that the individual extraocular muscles function individually, but that they may simply not be aimed at the same target.

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Concomitant strabismus in a child under the age of 6 rarely indicates serious neurologic disorder.

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Blindness in one eye usually causes concomitant strabismus, with the eye of a child turning inward, and that of an adult turning outward.

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Incomitant strabismus occurs when the degree of misalignment varies with the direction of gaze.

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This indicates that one or more of the extraocular muscles may not be functioning normally.

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Types of strabismus include:

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• esotropia, or one eye turning inward;
• exotropia, or one eye turning outward;
• hypertropia, or one eye turning upward.
• hypotropia, or one eye turning downward.

Medial strabismus manifests as the inability to abduct (move laterally) one's eye. This is usually caused by damage to the abducens nerve or abducens nucleus. The result is that the eye in its normal resting state deviates medially, as the movements of the medial rectus muscle are less opposed by the denervated lateral rectus muscle.

Related Topics:
Abducens nerve - Abducens nucleus - Medial rectus muscle - Lateral rectus muscle

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