What is Esotropia?
Esotropia is an eye misalignment where one eye is turned inward. The turn may be constant or intermittent. The eye turned in may always be the same eye or the condition may be called alternating esotropia when alternate eyes deviate. It is the most commonly occurring strabismus early in life. Congenital esotropia accounts for 50% of all strabismus.
- Esotropia is an inward turn of an eye.
- Esotropia and the symptoms may vary in frequency and severity.
- Treatment may include patching, glasses, vision therapy and/or surgery.
What is Esotropia in Children?
The 5 types of esotropia that most affect children include: infantile, accommodative, non-accommodative, divergence insufficiency, and microtropia/monofixation syndrome.
An infantile esotropia is usually constant and presents within the first year of life. It is typically a large angle deviation, latent nystagmus, crossfixation, a normal accommodative convergence to accommodation ratio, and an age-appropriate refractive error.
Accommodative esotropia occurs in children over 1 year of age. It is typically due to hyperopia and the angle and/or frequency of the esotropia is reduced when bifocal glasses with the correction are worn. Accommodative esotropia may also be associated with microtropia/monofixation syndrome.
This type of esotropia is not affected by accommodation. The onset is usually after 1 year of age and can be constant or intermittent.
Divergence Insufficiency Esotropia
This type is found in individuals 30 years of age and older. These patients have reduced fusional divergence amplitudes, the esotropia is worse at distance than near, and they may have trouble with driving due to double vision.
Microtropia/Monofixation Syndrome Esotropia
These patients have a central scotoma in one eye together with small angle suppression and the presence of peripheral fusion.
Risk Factors for Esotropia
Esotropia can be hereditary or acquired. There is no predilection for esotropia in age or gender. Esotropia in children can be due to refractive error or accommodation.
Symptoms may vary by frequency and severity of the esotropia. If an individual suppresses the deviated eye, the patient can develop amblyopia, a more severe angle or frequency of the strabismus (cross eyes). Adults with esotropia who may suppress the deviated eye may experience diplopia (double vision).
All patients with esotropia need a complete eye exam. The doctor will measure visual acuity, assess binocular function and stereopsis, evaluate motility, perform strabismus measurements at near, distance, and cardinal positions of gaze, measure fusional amplitudes, and complete a cycloplegic refraction.
How to Treat Esotropia
Esotropia may be treated with surgery or other nonsurgical solutions. Nonsurgical treatments often include patching, correction of full hyperopic refractive error, and divergence orthoptic exercises (vision therapy) for divergence insufficiency. Prism glasses can be used to relieve double vision or asthenopia in certain patients. Sometimes sensory esotropia can be improved by treating the underlying cause.
Surgery is performed on the extraocular muscles to provide binocular single vision, to relieve double vision, or to restore the eyes to a normal state of alignment. The prognosis for surgical success is best if the patient’s esotropia is intermittent versus constant and if the amblyopia has been treated.
Sometimes, amblyopia may not be fully corrected due to the strabismus, and surgery may be needed prior to fully correcting the amblyopia. Surgery should be performed as early as possible, typically a few months after the onset.