Strabismus is the medical term for eye misalignment. Pseudostrabismus refers to a false appearance of strabismus. [See figure 1].
The skin fold at the inner corner of the eyelids can be broad and is often associated with a broad flat nasal bridge (epicanthal folds or epicanthus). These features contribute to a cross eye appearance since there is less space (white area) between the iris and the inner corner of the eyelid. This is especially noticeable in pictures and when the child looks to the side so that one eye appears to be much further into the nose than it should be.
The Eye MD determines if the light reflexes from each eye are centered. The light should fall symmetrically within the pupils. If a true strabismus is present the light reflexes do not fall on the same position of each eye. A cover test (occluding one eye and then the other) confirms the findings. A complete eye exam is also performed to rule out potential causes of true strabismus such as unequal vision (amblyopia) or high refractive error (hyperopia / far-sightedness).
Another form of pseudo strabismus is known as a Postive Angle Kappa. This occurs when the light reflection is more towards the nose on one or both eyes than towards the center of the pupil. This gives the appearance that the eye is deviated outwards. A cover test as above, occluding one eye and then the other produces no movement, however, so this is another example of pseudo strabismus. .
True strabismus in a child can lead to permanent vision loss and is best treated early. If a child is suspected of having strabismus, an Eye MD evaluation is important. It may be difficult for a pediatrician to differentiate between true strabismus and pseudostrabismus.
Pseudostrabismus does not require treatment and the appearance tends to improve with time. As facial features mature, the widened nasal bridge tends to narrow. Asian children may retain a broad nasal bridge into adulthood.
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