What is Esotropia?
Esotropia is a form of eye misalignment (strabismus or crossed eyes).1 The condition is characterized by inwardly-deviated eyes (towards the nose).
Esotropia can affect one or both eyes and occurs in two ways:
- Constant, which means it’s present at all times
- Intermittent, or when the eye(s) turn inwards sometimes
Generally, people with esotropia are farsighted, meaning they have trouble seeing near objects but have good distance vision. Esotropia is common in babies younger than 3 years. In kids, it’s called infantile esotropia.
According to studies, the risk of esotropia increases with the mother’s age (up to 34 years) and is more common among white people than black people.2
If you experience double or blurry vision, or your baby has difficulty focusing on objects and people, seek medical assistance.
Types of Esotropia
There are several types of esotropia based on who they affect, how they occur, and their manifestations. Below are the common types:
Infantile esotropia occurs in children 6 to 12 months old.3 Associated eye problems may include farsightedness, upward drifting of the eyes, and nystagmus (uncontrollable eye movement).
Infantile esotropia has a constant angle of esodeviation, meaning the eye turn is constant. If only one eye is frequently affected, the child is at a higher risk of lazy eyes (amblyopia).
According to the American Academy of Ophthalmology, intermittent esotropia is normal up to 3 months after birth and resolves on its own. It should not be confused with infantile esotropia.
Acquired esotropia occurs later in life. It may indicate an underlying condition such as diabetes, eye problems such as thyroid eye disease, and neurological disorders such as myasthenia gravis and intracranial tumor.4
Acquired esotropia is associated with double vision (diplopia) and decreased visual field. It can disrupt everyday activities in older children and adults. Eyeglasses, contact lenses, vision therapy, or eye muscle surgery are the common treatment options for this condition.
Accommodative esotropia usually occurs after 1 year of age. It happens when someone strains their eyes to see clearly without using aids like eyeglasses or contacts. People with this type of esotropia may also have hyperopia (farsightedness).
Fortunately, accommodative esotropia can be corrected using eyeglasses or contact lenses. Your doctor may also recommend surgery if the condition persists.
If accommodative esotropia is partially corrected, meaning the hyperopia is fully corrected but residual esotropia persists, it’s referred to as partially accommodative esotropia.
This is esotropia that occurs after 1 year and before 5 years of age. It results from an imbalance of eye muscles and not accommodative efforts such as eye strain, which means wearing glasses or contact lenses isn’t a solution.
Non-accommodative esotropia can occur suddenly or result from uncorrected (or undercorrected) farsightedness, worsening esotropia, or recurrent esotropia.5
Divergence Insufficiency Type Esotropia
Divergence insufficiency esotropia is esodeviation that increases with distance. Also known as acquired comitant esotropia or “age-related distance esotropia,” it’s most often associated with adults (30 years and older).
Someone with divergence insufficiency may experience double vision when viewing distant objects.6 This is due to a larger angle of inward turning (esodeviation). Esodeviation decreases as the object moves closer.
Common treatments include prism therapy to correct double vision and surgery in cases of severe esotropia. Approved surgeries include lateral rectus recession and medial rectus recession. The medial rectus and lateral rectus are the muscles that enable horizontal eye movements.
This is esotropia of an eye with poor vision. In this case, the problematic eye cannot coordinate with the other eye, thus deviating inwards. This condition may affect children under 4 years or older and adults with sensory visual deprivation (loss of visual stimulation).
Consecutive esotropia occurs when someone with exotropia becomes esotropic. It can be due to surgical overcorrection of exotropia (outwardly turned eyes). Studies show a 6 to 20% incidence rate among previously treated exotropia cases.7
Generally, consecutive esotropia with slight deviation resolves with time. However, you may need treatment if diplopia persists, deviation increases, or eye movement is limited.
Esotropia Vs Exotropia
Esotropia is the inward turning of the eyes; exotropia is the direct opposite (outwardly turned eyes). Like esotropia, exotropia might be constant or intermittent (occasional).
Exotropia might occur at birth (congenital) or late in life and can affect people of all ages. It can also result from surgical overcorrection of constant esotropia.
What Causes Esotropia?
Esotropia results from muscle or neurological impairment. Usually, eye muscles work together in a binocular system that converts what both eyes see into a single visual image that the brain can interpret.
Any defects to the eye muscles or their enablers in the central nervous system (CNS) can affect eye coordination, leading to esotropic eyes.
Some people are born with esotropia (congenital esotropia), although this is rare. Most children acquire it several months after birth or later into their adulthood. Scientists also believe there’s a hereditary aspect to esotropia.8
The known risk factors of acquiring esotropia include:
- Constant eye strain, especially if you’re farsighted
- Eye/head trauma
- Systemic disorders such as diabetes
- Positive family history of strabismus (eye misalignment)
- Genetic disorders such as Down Syndrome
- Neurodegenerative conditions, such as Parkinson’s disease or cerebral palsy
- Eye movement disorders such as Duane syndrome (inability to move the eyes)
- Premature birth
- Eye disorders, such as cataracts or glaucoma
- Stroke or other vascular issues
- Immune system disorders such as Graves’ disease
If strabismus runs in your family, have your child’s eyes checked out as a precaution.
Symptoms of Esotropia
Esotropia symptoms include:
- Uncoordinated eyes
- Squinting or straining your eyes to see clearly
- Poor depth perception (inability to perceive the distance between objects)
- Diplopia (double vision)
- Amblyopia (lazy eye)
People with esotropia may be unable to focus their eyes on one object at a time. They may have to use one eye to see an object fully.
How is Esotropia Diagnosed?
An ophthalmologist makes a diagnosis of esotropia. They will first review your medical and family history before carrying out eye examinations. The tests check for:
- Vision clarity in both eyes
- Retinal function
- Eye coordination
- Your eyes’ ability to refract light
- The extent of farsightedness (hyperopia)
How to Treat Esotropia
Esotropia may resolve without any intervention in children younger than 5 months and with mild symptoms of misalignment. However, some cases may require professional treatment.
Treatment for esotropia depends on:
- Whether one or both eyes are affected
- Whether your esotropia is accommodative or not
- Severity of the condition
- Length of persistence
Common treatments for esotropia include:
- Prescription glasses or contact lenses. Prescription glasses with bifocal or prism lenses can correct eye misalignment or farsightedness.
- Vision therapy. Eye exercises can strengthen your muscles and improve the function of the crossed eyes.
- Botulinum Toxin A (Botox) injections. Injected to realign the eyes in people with consecutive esotropia alongside binocular vision.
- Surgery. Some people may require lateral or medial rectus recession to fix defective eye muscles.
Surgery mainly benefits infants with esotropia, but some affected adults may also qualify.
Complications of esotropia include:
- Diplopia (double vision)
- Decreased binocular vision
- Poor depth perception in children and adults
- Loss of 3D vision in children
- Amblyopia (loss of vision)
Treating esotropia early during infancy will reduce the risk of long-term complications.
Do the following to prevent esotropia:
- Wear prescription eyeglasses or contact lenses if you’re farsighted (don’t strain your eyes)
- Seek immediate medical attention if you experience double vision or notice pupil misalignment
- Take your child for a checkup if esotropia runs in your family
- Treat eye disorders and other underlying conditions such as diabetes
- Avoid situations that put you at risk of eye or head trauma
The global prevalence of esotropia is 0.77%. The condition affects about 1 to 3% of the U.S. population.10 Although it may resolve on its own, especially if it occurs intermittently during childhood, treatment might be necessary in severe cases.
Without early treatment, esotropia will worsen, leading to complications, including permanent vision loss.
- Esotropia is a form of eye misalignment characterized by inwardly turned eyes
- It can affect one or both eyes and occurs in two ways
- Esotropia can be constant or intermittent and can affect people of all ages
- Common types include infantile, acquired, accommodative, non-accommodative, sensory, and consecutive esotropia
- Causes of esotropia include head injury, genetics, eye disorders, eye strain, and underlying medical conditions such as diabetes
- Esotropia may resolve on its own, but severe cases may require treatment, including strabismus surgery
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