Infantile Esotropia - Causes, Symptoms, Diagnosis and Treatment

What Is Infantile Esotropia?

Esotropia refers to the inward turning of one or both eyes. When esotropia occurs within the first year of life, it is termed infantile esotropia. This condition is also known as congenital esotropia, though the term "infantile" is preferred because it may not always manifest immediately after birth.

What Are the Causes of Infantile Esotropia?

Infantile esotropia may be caused due to various reasons, some of the following are:

1. Weak Muscles - The duration of the onset of esotropia from zero to six months has a strong reason. This is the period during which the eye musculature develops and becomes strong. At times, the muscles of both eyes may not be in sync with each other. The exact reason behind this is unknown. Hence, a discrepancy may occur in the eye movements.

2. Family History of Esotropia - The infant presenting with esotropia may present with a strong familial history. A strong family history puts some infants at greater risk of developing esotropia than others. In such cases, it may be observed that a few other family members, such as a sibling or parent, may also present with strabismus.

3. Trauma to the Eye Musculature - Trauma to the eye muscles can lead to the eyes not being in union with each other, ultimately leading to esotropia.

4. Congenital Cataract - Some babies can be born with cataracts, which cloud around the cornea. At times, during the surgical correction of cataracts, esotropia can be caused.

5. Refractive Errors - At times, babies may be born with refractive errors such as farsightedness. Uncorrected refractive errors can lead to muscular weakness, ultimately leading to esotropia.

6. Neurological Issues - Inherent issues of the nerves can lead to crossed eyes. Any congenital or acquired issues with the nerves supplying the eye muscles can lead to the loosening of the muscle structure. A loose muscle will give rise to crossed eyes.

7. Premature Babies - Premature babies may develop crossed eyes if the eye muscles are not fully developed.

8. Systemic Conditions - Esotropia can be seen in many systemic conditions, such as Down syndrome and cerebral palsy.

What Is the Risk Factor of Infantile Esotropia?

Congenital esotropia appears to have a complex genetic basis involving multiple factors, although specific genes have not yet been pinpointed. It is observed that primary monofixation syndrome occurs 11 times more frequently among first-degree relatives of individuals with infantile esotropia compared to the general population. Prematurity and low birth weight are also linked to a higher risk of infantile esotropia.

How Is Infantile Esotropia Diagnosed?

• Medical History: Thoroughly documenting gestational age at birth, birth weight, birth-related complications, overall health status, and developmental milestones can aid in managing the case. Gathering a detailed history from the initial presentation, supported by photographs of the child during the early months, helps document the onset, assess the stability of the condition, and confirm the diagnosis. Family history can provide insights into potential genetic factors or familial inheritance.

• Physical Examination: Achieving an accurate diagnosis and effective management involves conducting a comprehensive ophthalmologic evaluation, which includes cycloplegia and dilation. This examination is crucial for identifying other potential causes of esotropia in young children, such as media opacities, refractive errors, or cranial nerve palsy. Assessing motility and alignment requires a detailed examination, which can be challenging in young children. It is important to perform the exam quickly and in a playful environment. Engaging the child's attention with colorful toys, whistling, and making noises can help create a positive and cooperative atmosphere during the examination.

Do Children With Infantile Esotropia Experience Vision Loss?

Individuals with infantile esotropia typically maintain good vision in both eyes. However, if one eye is consistently turned inward more than the other, there is a risk of developing poor or blurry vision (amblyopia). When a baby with crossed eyes uses each eye equally, the likelihood of amblyopia is reduced. Amblyopia occurs when there is diminished vision in one eye because the brain does not adequately utilize or connect with that eye.

Do Individuals With Infantile Esotropia Require Glasses?

Children with infantile esotropia typically do not require glasses more than children with straight eyes. However, glasses may be prescribed if these children have significant farsightedness, nearsightedness, or astigmatism.

What Is the Treatment of Infantile Esotropia?

Although, in most cases, this condition may resolve on its own, sometimes it may require treatment. Treatment of this crossed eye is entirely dependent on its cause. Correction of the cause can lead to the resolution of the disease. The ultimate aim of the treatment is to strengthen the eye muscles. The various available treatment options are:

1. Eye Glasses - In case of esotropia caused due to refractive errors, eyeglasses can be prescribed to rectify the underlying condition, leading to resolution of the condition. Eyeglasses will help to balance the action of the muscles. It will help the weaker eye muscles to correct themselves.

2. Helping the Eye To Correct Itself - In conditions wherein only one of the eyes is affected, certain mechanisms can be applied to the normal eye to help the affected eye to correct itself. Such methods include:

• Using blurred glasses on the normal eye.

• Using eye drops that can make the normal eye blurry.

• Using eye patches on the normal eye.

3. Surgical Methods - In case of failure of the aforementioned treatments, surgical treatment may be required. The muscles that are responsible for this condition will be corrected using surgical intervention. The muscles can be tightened or loosened depending on the individual condition. This treatment largely has a good prognosis.

4. Usage of Botox Injections - Usage of Botox injections will loosen the eye muscles, aiding in its correction.

What Are the Differential Diagnosis of Infantile Esotropia?

• Infantile Myasthenia Gravis (congenital muscle weakness due to autoimmune antibody attack).

• Pseudoesotropia (eye misalignment appearance, normal alignment, no treatment needed).

• Mobius syndrome (facial paralysis, limb abnormalities, no lateral eye movement).

• Sensory esotropia (eye turns inward due to poor vision, unilateral).

• Congenital fibrosis syndrome (restricted eye movement due to extraocular muscle fibrosis).

• Congenital sixth nerve palsy (impaired eye movement outward, due to sixth nerve).

• Ciancia syndrome (congenital syndrome affecting eye movement and facial expression).

• Nystagmus blockage syndrome (eye movement disorder worsened by blocking normal vision).

• Type I Duane’s syndrome (limited eye movement, especially outward, congenital condition).

• Esotropia is linked to neurological conditions such as cerebral palsy and periventricular encephalomalacia.

Conclusion:

Esotropia, like many other conditions, is not preventable. Even when it does not resolve on its own, multiple treatment options are available to rectify the crossed eye. However, the treatment and rectification depend on the early and prompt diagnosis of the condition. It is better to report the condition to one's pediatrician as soon as it is noticed. Treatment may be suggested if the condition does not resolve on its own, even after four months. If the treatment is delayed, it may lead to conditions like lazy eye syndrome. Due to this, other milestones of development may also be delayed. Hence, it is advisable to receive treatment as soon as possible to achieve a healthy vision for the kid.