What is Exotropia?

Exotropia is a form of strabismus (eye misalignment) in which eyes do not line up properly. The muscles that normally control the eyes are not synchronized as they should be. In this eye disorder, one or both eyes point outward. What is more, it can affect only one eye (monocular) or both eyes (binocular). The prevalence of strabismus is estimated at 1%–3% of the population. In this blog post, we will explore the causes, types, symptoms, diagnosis, treatment, and what happens if exotropia is left untreated.

Causes

The causes can be unknown. However, several factors can contribute to the development of exotropia:

1. Eye muscles imbalance: Exotropia often occurs due to a muscle imbalance in the eyes. If the muscles responsible for controlling eye movement are not properly working together, one or both eyes may deviate outward.

2. Genetics: There is evidence to suggest that genetics play a role in exotropia. Children with a family history of strabismus are more likely to develop the condition.

3. Refractive errors: Uncorrected or untreated refractive errors, such as nearsightedness (myopia) or farsightedness (hyperopia), can contribute to the development of exotropia.

4. Neurological conditions: Certain neurological conditions, such as cerebral palsy or Down syndrome, can increase the likelihood of developing exotropia.

5. Low vision: Having low vision can result in exotropia.

Types of Exotropia

There are a lot of types of exotropia. The broadest and easiest distinction is between constant and intermittent exotropia.

Intermittent exotropia

The most prevalent type of exotropia is intermittent exotropia. It usually happens after the first year of age. What is more, it is estimated that around 1% of population has it.

Intermittent means that exotropia is not present all the time. Individuals suffer outward drift occasionally, such as when they are sleepy, feeling unwell, experiencing stress, and focusing on distant objects. Children may squint or rub one of their eyes, in conjunction with bright light. When their eyes are misaligned, some people report that their vision gets fuzzy or that they experience double vision.

Constant exotropia

With constant exotropia, eyes are always turned outward. This condition is less common compared to intermittent exotropia.

Other Types

Additionally, there are also other types of exotropia.

Congenital (infantile) exotropia

This is a type of exotropia that is present at birth.

Sensory exotropia

Sensory exotropia can occur due to visual loss at any age. The eye with poor vision turns outward. It is characterized by large deviation angles and these deviations are constant. Binocular vision is disrupted.

Alternating exotropia

Exotropia that occurs in both eyes at different periods.

Consecutive (secondary) exotropia

Such exotropia develops after surgery to treat crossed eyes, more specifically, esotropia.

Symptoms of Exotropia

Other symptoms, besides outward deviation of one or both eyes, especially noticeable when tired or focusing on distant objects include:

– Double vision (diplopia)
– Blurred vision
– Squinting
– Eye strain or discomfort
– Headache
– Closing one eye in the light
– Decreased depth perception

Diagnosis

When suspecting exotropia, the first step is to schedule a comprehensive eye examination with an ophthalmologist or optometrist.

1. Medical history: The eye care professional will review the patient’s medical history, including any family history of eye conditions or strabismus.

2. Visual acuity test: A visual acuity test is performed to assess how clearly a person sees objects at various distances. This test involves reading letters or symbols from a standardized eye chart.

3. Ocular alignment assessment: The eye care professional will carefully observe the alignment of the eyes in different gaze positions, both at rest and during eye movement. They will check for any deviation or misalignment, particularly noting any outward turning of the eyes.

4. Cover test: The cover test is a diagnostic tool used to detect eye misalignment and assess the presence of strabismus. By covering one eye at a time and observing how the eyes move when uncovered, the doctor can determine if there is any ocular deviation.

5. Refraction test: A refraction test is conducted to assess the refractive errors, such as nearsightedness (myopia) or farsightedness (hyperopia), that may be contributing to the exotropia. This test helps determine if corrective lenses, such as eyeglasses or contact lenses, are necessary.

6. Binocular vision assessment: Binocular vision tests evaluate the ability of both eyes to work together as a team. These tests include the assessment of depth perception, stereopsis (the perception of depth and 3D vision), and eye coordination.

Additional Diagnostic Tools

In some cases, further evaluation may be required to gather more detailed information about the exotropia. Eye care professionals may use additional diagnostic tools and techniques, such as:

Cycloplegic Refraction: This test involves using eye drops to temporarily paralyze the focusing muscles of the eyes. By doing so, the eye care professional can obtain accurate measurements of the patient’s refractive errors.

Retinal Examination: A retinal examination, which may involve dilating the pupils, allows the doctor to examine the back of the eye, including the retina and optic nerve. This examination helps rule out any underlying eye conditions or abnormalities that may be contributing to the exotropia.

Imaging Studies: In some complex cases, imaging studies like magnetic resonance imaging (MRI) or computed tomography (CT) scans may be necessary to assess the structures of the eye, orbit, and surrounding tissues.

Treatment

1. Eye patching or occlusion therapy: In some cases, the stronger eye may be patched or temporarily covered to encourage the weaker eye to work harder, promoting better alignment.

2. Eye drops: Medical form of patching.

3. Corrective lenses: If exotropia is associated with refractive errors, prescription eyeglasses can help correct the imbalance, improving eye alignment.

4. Eye exercises or vision therapy: This non-surgical treatment involves a series of exercises and activities designed to improve eye coordination and strengthen the eye muscles. Vision therapy is often beneficial for both children and adults.

5. Surgical intervention: Surgery can be used to tighten or loosen muscles in one or both eyes. The surgical procedure aims to adjust the positioning of the eye muscles to achieve better eye alignment.

Read about the Experiences of Individuals with Exotropia and AmblyoPlay

Ula: Mother of 4-years old girl with intermittent exotropia

We’ve been using AmbloPlay for the last 6 months on a daily basis trying to improve our 4 years old daughter intermittent exotropia on both eyes. We can see a significant improvement and even a doctor said it must work even though he is skeptical about vision therapy. so we gonna keep up on using this great tool. Thank you to all who have invented this therapy!

What Happens if I do not Treat Exotropia?

If left untreated, exotropia might result in amblyopia, or poor vision in one eye. Furthermore, you may lose your ability to see with both eyes (binocular vision) and have trouble with depth perception.

Conclusion

Exotropia can occur in various forms, ranging from intermittent to constant deviations. It may manifest in childhood or develop later in life due to underlying factors such as muscle imbalances, neurological conditions, or refractive errors. While the exact cause of exotropia is not always clear, early detection and intervention are crucial to prevent potential vision problems and promote optimal visual development.

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