Strabismia

Strabismia, sometimes used as a variant term for strabismus, is a condition in which the eyes are misaligned and do not look at the same point when focusing on an object. The brain may suppress input from one eye to avoid diplopia, which can lead to reduced binocular vision and depth perception if not treated.

Types and signs include deviations that may be constant or intermittent. Common forms are esotropia (inward turning of one eye), exotropia (outward turning), hypertropia (eye drifts upward), and hypotropia (eye drifts downward). In children, signs often include a visible squint, bringing the head to one side, or frequent rubbing of the eye. Adults may experience double vision and eye strain.

Causes and risk factors are multifactorial. They can involve refractive errors, congenital abnormalities of the eye muscles or nerves, neuromuscular conditions, trauma, or syndromic associations. Risk factors include prematurity, a family history of strabismus, and certain developmental disorders.

Diagnosis relies on a comprehensive eye examination to assess alignment and visual function. Eye care professionals use tests such as the cover-uncover and alternate cover tests, light reflex tests, and cycloplegic refraction, along with assessments of visual acuity and binocular function to determine the type and severity of the misalignment.

Treatment depends on age, type, and underlying cause. Options include corrective glasses, prisms, occlusion therapy to prevent amblyopia in children, vision therapy, and botulinum toxin injections. In many cases, surgery on the extraocular muscles may be considered to improve alignment.

Prognosis improves with early detection and appropriate management. Untreated strabismia can lead to persistent amblyopia, reduced depth perception, and social or functional issues, making ongoing follow-up important.