Strabismus

Strabismus is a condition where there is misalignment of the visual axes of the eyes; it may be latent or manifest and, if manifest, it may be constant or intermittent.

It is a common cause of diplopia (double vision) and visual confusion (seeing different objects in the same place) in adults.

It is an important cause of amblyopia (decreased vision in an anatomically normal eye caused by suppression) in children.

It may be aesthetically obvious to the patient and others, resulting in psychosocial problems.

Evaluation involves a detailed medical history, including a complete ocular history, followed by thorough neurological and ophthalmic examinations.

Treatment is directed at restoring and maintaining ocular alignment, eliminating diplopia or visual confusion, enabling binocular vision, and restoring normal appearance.

If strabismus is secondary to an underlying cause (e.g., abducens nerve [cranial nerve VI] palsy causing esotropia [inwards deviation of one or both eyes]), treatment of this condition is necessary.

Strabismus refers to a misalignment of the eyes. If strabismus develops in adults, it can cause diplopia (double vision) and visual confusion (seeing different objects in the same location), and it is an important cause of amblyopia in children.[1]US Preventive Services Task Force. Vision in children ages 6 months to 5 years: screening. Sep 2017 [internet publication]. https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/vision-in-children-ages-6-months-to-5-years-screening Whereas normally both eyes fixate (look at) the object of interest, in strabismus one eye fixates and the other (non-fixating eye) is deviated.

The most common types of strabismus are esotropia, where there is inwards deviation, and exotropia, where there is outwards deviation.[2]Wallace DK, Christiansen SP, Sprunger DT, et al. Esotropia and exotropia preferred practice pattern®. Ophthalmology. 2017 Nov 4;125(1):P143-83. https://www.aao.org/preferred-practice-pattern/esotropia-exotropia-ppp-2017 http://www.ncbi.nlm.nih.gov/pubmed/29108746?tool=bestpractice.com With hypertropia, there is upwards deviation of the visual axis of one eye relative to the other. With hypotropia, there is downwards deviation of the visual axis of one eye relative to the other. 

Strabismus can be classified as comitant (concomitant) or incomitant (non-comitant). With comitant strabismus, the deviation does not vary in size with the direction of gaze. Comitant strabismus makes up most forms of childhood strabismus. With incomitant strabismus, the deviation varies in size with the direction of gaze. Here, the strabismus is often paralytic or restrictive in nature, and may indicate underlying neurological or orbital disease.

See Classification.