What is Strabismus?
Strabismus is a condition in which the eyes do not look in the same direction at the same time. One eye may look straight ahead while the other turns inward, outward, upward, or downward. This misalignment can be constant or intermittent, affecting one eye or alternating between both. The condition is often a result of a lack of coordination between the eye muscles.
Types of Strabismus
Strabismus is classified by the direction of the eye's misalignment.
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Esotropia: The eye turns inward, often referred to as being "crossed."
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Exotropia: The eye turns outward, sometimes called a "wall-eye."
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Hypertropia: The eye turns upward.
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Hypotropia: The eye turns downward.
Symptoms of Strabismus
The symptoms of strabismus can vary depending on the severity and age of the patient. In children, it may not always be immediately obvious. Symptoms often include:
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Misaligned eyes: One eye appears to be looking in a different direction.
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Double vision: More common in adults, as the brain struggles to merge two different images.
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Loss of depth perception: Difficulty judging distances.
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Eye strain or fatigue.
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Headaches.
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Squinting or tilting the head to see clearly.
Causes of Strabismus
The precise cause of strabismus is not fully understood, but it is typically a problem with the neuromuscular control of the eye movements.
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Risk Factors
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Genetics: A family history of strabismus increases the risk.
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Refractive Errors: Uncorrected farsightedness (hyperopia) can sometimes lead to esotropia as the eyes strain to focus.
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Medical Conditions: Conditions such as cerebral palsy, Down syndrome, or hydrocephalus are associated with strabismus.
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Eye Injury or Illness: Damage to the eye, retina, or optic nerve can cause eye misalignment.
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Diagnosis of Strabismus
An ophthalmologist can diagnose strabismus during a comprehensive eye examination. Early diagnosis is particularly important in children to prevent long-term vision problems. The diagnosis typically involves:
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A visual acuity test: To assess the patient's vision.
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Corneal light reflex test: The doctor shines a light into the patient's eyes and observes where the light reflects from the cornea. In properly aligned eyes, the light reflex is centered in each pupil.
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Cover/uncover test: This simple yet effective test helps the doctor determine if the eyes are misaligned and the direction of the deviation.
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Dilated eye exam: To check for underlying eye conditions that may be causing the strabismus.
Treatment of Strabismus
The primary goal of strabismus treatment is to improve eye alignment, restore binocular vision (the ability to use both eyes together), and prevent long-term vision problems like amblyopia.
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Non-Surgical Treatments
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Glasses or Contact Lenses: Used to correct underlying refractive errors, which can sometimes resolve the strabismus, especially in cases caused by farsightedness.
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Prism Lenses: Special lenses that bend light to help the eyes work together and reduce double vision.
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Surgical Treatment
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Strabismus Surgery: This is the most common treatment for persistent eye misalignment. The surgeon adjusts the eye muscles to properly align the eyes. This is a very common procedure in both children and adults and is performed under general or local anesthesia.
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