STRABISMUS (SQUINT)

What is a Strabismus?

Strabismus (squint) is caused because of a lack of muscle coordination between the eyes, causing the eyes to point in different directions.

The eyes are unable to focus simultaneously on a single point.

The eyes are misaligned and point in different directions. The misalignment may always be noticeable, or it may come and go. One eye may be directed straight ahead, while the other eye is turned inward, outward, upward or downward. The turned eye may straighten at times and the straight eye may turn.

Common Terms for Strabismus

Lazy Eye, Turned Eye, Crossed Eyes

Who is Affected by Strabismus?

Strabismus is most common among children, affecting about four per cent but can also occur later in life. It occurs equally in males and females and may run in families. However, many people with strabismus have no relatives with the problem.

Causes of Strabismus

Strabismus may result from problems with the extraocular muscles or their nerves, blindness, mechanical problems in the eye, or mechanical obstruction to vision in one eye during early life.

Symptoms of Strabismus

In adults, strabismus may be a symptom of various brain disorders or systemic diseases. Squint surgery aims at re-aligning the eye muscles.

Types of Strabismus

Most common types are:

Exotropia - the outward turning of the eyes
Esotropia - the eyes are 'crossed'

Stages of Strabismus

When one eye turns, as in strabismus, two different pictures are sent to the brain. In a young child, the brain learns to ignore the image of the misaligned eye and sees only the image from the straight or best-seeing eye. This causes loss of depth perception and binocular vision.

Adults who develop strabismus often have double vision because the brain is already trained to receive images from both eyes and cannot ignore the image from the turned eye.

How is Strabismus Treated?

Treatment for strabismus is most effective when the child is young.

Straightening of the eyes remains possible at any age and can result in improved side vision.

Treatment for strabismus may be non-surgical and include eye drops, exercises or glasses.

If surgical treatment is indicated, the earlier in life it is done, the better chance the child has of developing normal binocular vision.

After a complete eye examination, including a detailed study of the inner parts of the eye, an ophthalmologist can recommend appropriate optical, medical or surgical therapy.

Treatment goals for strabismus are to preserve vision, to straighten the eyes, and to restore binocular vision.

Covering or patching the good eye to improve vision in the amblyopic eye is often necessary.

Depending on the cause of the strabismus, treatment may involve surgical repositioning the unbalanced eye muscles, removing a cataract, correcting other Strabismus, which are causing the eyes to turn, or carefully delivered botox injections.