Esotropia: Symptoms, Types, Causes and Treatment

Esotropia, commonly referred to as "crossed eyes," is a form of strabismus where one or both eyes turn inward. This condition can affect people of all ages, but is especially prevalent in children. Early recognition and treatment are crucial to preserve vision, prevent amblyopia (lazy eye), and ensure healthy binocular function. In this article, we’ll explore esotropia in depth—covering its symptoms, the main types, underlying causes, and the latest treatment options.

Symptoms of Esotropia

Esotropia can sometimes be subtle, but there are hallmark symptoms that caregivers and patients often notice. Recognizing these early is vital for timely intervention and the best possible visual outcomes.

Symptom	Description	Frequency/Population	Source(s)
Eye Inward Turn	One or both eyes turn toward the nose	Most common presentation	2 3 6 7
Diplopia	Double vision, especially in acquired forms	More common in adults	7 8 9 10
Amblyopia	Decreased vision in one eye due to misalignment	Frequent in children	2 3 6 13
Eye Fatigue	Ocular discomfort, especially with near work	Variable	1 7 8
Headaches	Due to visual strain or compensation efforts	Some patients, especially adults	1 7 9
Abnormal Stereoacuity	Reduced depth perception or 3D vision	Children & adults	1 3 8 9

Table 1: Key Symptoms

Eye Inward Turn and Appearance

The defining symptom of esotropia is the visible inward deviation of one or both eyes. This misalignment may be constant or intermittent. In some children, the turn is subtle and only appears when they're tired or focusing on close objects. In congenital or infantile forms, the turn is often large and easily noticed by parents or caregivers 2 3 6 13.

Diplopia (Double Vision)

Adults or older children who develop esotropia after their visual system has matured may experience double vision (diplopia). This occurs because the brain receives conflicting images from each eye, which it struggles to fuse 7 8 9 10. Younger children rarely report diplopia because their brains often suppress the image from the misaligned eye, but this leads to the risk of amblyopia.

Amblyopia (Lazy Eye)

When the brain ignores input from the deviated eye to avoid double vision, amblyopia can develop. This is particularly concerning in early childhood, as it can lead to permanent visual impairment if not addressed 2 3 6 13.

Eye Fatigue and Headaches

Esotropia can cause significant visual discomfort, including eye fatigue and headaches. Some patients report worsening symptoms during tasks requiring intense focus, such as reading or viewing 3D images 1. In some cases, eye fatigue is more pronounced in those with exodeviation (outward turning), but headaches and discomfort can still occur in esotropic patients, particularly those with recent onset or decompensated forms 1 7 9.

Abnormal Stereoacuity (Depth Perception)

Reduced stereopsis, or depth perception, is a common finding in esotropia. This impairment can affect school performance, sports, and daily life, especially if the misalignment is present during key developmental periods 1 3 8 9.

Types of Esotropia

Esotropia is not a single disease, but a spectrum of conditions with varying underlying mechanisms and clinical features. Understanding the different types is critical for accurate diagnosis and effective management.

Type	Defining Features	Age of Onset / Population	Source(s)
Accommodative Esotropia	Related to focusing effort (hyperopia), often intermittent at first	1.5–4 years (children)	2 3 6
Congenital/Infantile	Constant, large-angle deviation, onset before 6 months	Infants	2 3 5 11 13
Acquired Nonaccommodative	Not linked to focusing, sudden/gradual onset	Children & adults	2 3 4 7 9
Sensory Esotropia	Due to poor vision in one eye	All ages	2 3 10
Paralytic Esotropia	Caused by nerve palsies (esp. CN VI)	Adults > Children	2 3 10
Decompensated Esophoria	Latent inward tendency becomes manifest	Older children/adults	4 8 9
Age-related Distance Esotropia	Inward turn greater at distance, seen in elderly	Older adults	4 10

Table 2: Main Types of Esotropia

Accommodative Esotropia

This is the most common form in children. It arises when children with uncorrected hyperopia (farsightedness) over-focus to see clearly, causing their eyes to cross. Initially, the deviation may be intermittent and often becomes more constant without correction. Corrective lenses can often resolve the alignment 2 3 6.

Congenital or Infantile Esotropia

Appearing within the first six months of life, this form is characterized by a large, constant inward deviation. It is not related to refractive error and often requires surgery for correction. These children are at high risk of developing amblyopia and poor binocular vision if not treated early 2 3 5 11 13.

Acquired Nonaccommodative Esotropia

This type is seen in both children and adults, with onset after infancy, and is not associated with the accommodative effort. Causes can include neurological issues, trauma, or idiopathic factors. It often presents suddenly and may be associated with diplopia 2 3 4 7 9.

Sensory and Paralytic Esotropia

Sensory esotropia occurs secondary to vision loss in one eye, leading the eye to drift inward. Paralytic esotropia is typically due to cranial nerve VI palsy, resulting in limited ability to move the eye outward 2 3 10.

Decompensated Esophoria

Individuals may have a latent inward tendency (esophoria) that, over time or under stress, becomes a constant esotropia. This often presents in school-aged children or adults and may be triggered by illness, fatigue, or visual stress 4 8 9.

Age-related Distance Esotropia

More common in older adults, this form presents as an inward turn that is greater when looking at distant objects. It is thought to be related to age-associated changes in the eye muscles or their nerve supply 4 10.

Causes of Esotropia

The origins of esotropia are diverse, involving genetic, anatomical, neurological, and environmental factors. Pinpointing the cause is key for personalized treatment.

Cause	Mechanism / Risk Factor	Typical Type(s)	Source(s)
Hyperopia	Excessive focusing effort triggers inward turn	Accommodative	6 7 9
Genetics/Family History	Inherited predisposition	Multiple types	2 3 6
Neurological Disorders	Affects control of eye movement	Acquired, paralytic	2 4 7 9 10
Sensory Visual Loss	Drives eye to drift inward	Sensory	2 3 10
Age-related Changes	Muscle/nerve degeneration	Distance, paralytic	4 10
Decompensation of Phoria	Latent misalignment becomes manifest	Decompensated esophoria	4 8 9
Trauma or Tumor	Directly affects muscle/nerve function	Paralytic, acquired	4 9 10

Table 3: Underlying Causes

Hyperopia and Accommodation

A major cause of esotropia in children is uncorrected hyperopia. The extra effort required to focus leads to excessive convergence of the eyes, resulting in accommodative esotropia. Glasses that correct the hyperopia often resolve the crossing 6 7 9.

Genetic and Familial Factors

Family history plays a significant role—children with relatives who had strabismus are at higher risk. This points to a genetic predisposition that can interact with other risk factors 2 3 6.

Neurological Causes

Conditions affecting the brain or nerves controlling eye movement (like cranial nerve VI palsy, Arnold Chiari malformation, or cerebellar disease) can cause acute or chronic esotropia. Any acute onset, especially with neurological symptoms (headache, imbalance, nystagmus), should trigger urgent evaluation 4 7 9 10.

Sensory Visual Loss

Significant vision loss in one eye due to cataract, retinal disease, or trauma can lead to sensory esotropia at any age. The affected eye loses the stimulus to maintain alignment and drifts inward 2 3 10.

Age-related and Mechanical Changes

Degeneration of the extraocular muscles or their nerve supply with age can manifest as distance esotropia in older adults. Similarly, trauma or orbital tumors can mechanically impair muscle function, causing esotropia 4 10.

Decompensated Esophoria

In some individuals, a latent inward drift (esophoria) becomes manifest due to fatigue, illness, or simply with age. This can be triggered by prolonged near work or other visual stressors 4 8 9.

Treatment of Esotropia

Treatment for esotropia is highly individualized, depending on the type, severity, and underlying cause. The main goals are to align the eyes, restore binocular vision, and prevent amblyopia.

Treatment Option	Main Use	Success/Considerations	Source(s)
Glasses/Optical Correction	Hyperopia, accommodative types	Highly effective in AE, up to 70%	6 7 9
Patching/Occlusion	Prevent/treat amblyopia	Used in children	2 3 6 13
Surgery (Strabismus)	Congenital, nonaccommodative, persistent	Success rates 60-95% by type	5 11 13
Botulinum Toxin	Congenital, acquired, acute-onset	Comparable to surgery in selected cases	12 14 15
Prisms	Mild, intermittent, or adult-onset cases	Symptomatic relief, not curative	7 8 10
Treat Underlying Disease	Neurological, sensory, trauma causes	Essential for secondary types	4 7 9 10

Table 4: Treatment Approaches

Glasses and Optical Correction

For accommodative esotropia, prescribing glasses to correct hyperopia is often curative. Children may need bifocals if the deviation persists at near. Up to 70% can achieve excellent alignment with optical correction alone 6 7 9.

Patching and Amblyopia Therapy

If amblyopia is present, patching the stronger eye or using atropine drops can encourage use of the weaker eye and improve vision. This is most effective when started early in childhood 2 3 6 13.

Surgery

Strabismus surgery is indicated when optical correction fails, or for nonaccommodative, congenital, or large-angle esotropia. Surgical approaches include medial rectus recession, posterior fixation sutures, or multi-muscle procedures. Success rates are generally high, but multiple surgeries may be needed, especially in infantile esotropia 5 11 13.

• Posterior Fixation Sutures (PFS): Shown to be effective as a first-line procedure in various esotropia subtypes, with success rates up to 95% 5.
• Botulinum Toxin: An emerging alternative, especially valuable in children and acute-onset cases. Studies show it's as effective as surgery in many cases, with lower cost and less anesthesia time 12 14 15.
• Botulinum Toxin for Infantile Esotropia: Success rates up to 76% have been reported, with minimal risk of serious complications 12.

Prisms

For mild deviations or adults with persistent diplopia, prisms can help realign images and relieve symptoms. This is often a temporary or adjunctive measure 7 8 10.

Treating Underlying Causes

In cases of paralytic, sensory, or neurologically-based esotropia, addressing the primary disease (e.g., removing a tumor, treating thyroid eye disease) is essential 4 7 9 10.

Special Considerations

• Neuroimaging: Not always required in isolated esotropia, but essential when neurological symptoms are present (headache, imbalance, nystagmus) or if the presentation is atypical 4 7 9.
• Long-term Follow-up: Especially important in children to monitor for recurrence, amblyopia, or late-onset binocular vision problems 4 11 13.

Conclusion

Esotropia is a complex condition with a wide spectrum of presentations, causes, and treatments. Early recognition and tailored management are key to preserving vision and ensuring the best outcomes.

Main Points:

• Symptoms include inward eye turn, double vision (mainly in older patients), reduced depth perception, and risk of amblyopia.
• Types range from accommodative and congenital to acquired, sensory, paralytic, and age-related forms.
• Causes are diverse: uncorrected hyperopia, genetic factors, neurological conditions, vision loss, age-related changes, and decompensated phorias.
• Treatment includes glasses, patching, surgery, botulinum toxin, prisms, and addressing any underlying disease. Most children with accommodative esotropia respond well to glasses, while surgery and botulinum toxin are effective for other types.
• Timely intervention is crucial to prevent permanent vision loss and to restore binocular vision and quality of life.

If you or your child is showing signs of esotropia, seek evaluation by an eye care professional promptly—early action can make all the difference.