Strabismus

Eye misalignment, crossed or wandering eyes

Overview

Strabismus is a misalignment of the eyes, so that they do not point at the same object at the same time. Esotropia is an inward turn, exotropia an outward drift, and hypertropia or hypotropia a vertical deviation, and a deviation may be constant or intermittent. In childhood, strabismus can lead to amblyopia and loss of binocular depth perception, because the developing brain suppresses the image from the deviating eye. Causes include refractive error, as in accommodative esotropia, abnormalities of eye muscle control, neurological conditions, and some genetic syndromes. Adults who develop new strabismus usually experience double vision, and acquired causes include cranial nerve palsies, thyroid eye disease, myasthenia gravis, and stroke. Pseudostrabismus, an appearance of crossed eyes in infants caused by a broad nasal bridge, is a common mimic. Management options include glasses, prisms, patching for associated amblyopia, botulinum toxin injection, and surgery on the extraocular muscles, and long standing childhood strabismus can also be surgically corrected in adulthood.