What is Strabismus?
Strabismus is a visual disorder in which the eyes are misaligned and point in different directions. This misalignment can happen partially (intermittent) or all of the time (constant).
Strabismus is characterized according to the direction of misalignment. When one of the eye is looking straight ahead, the other eye may turn inward (esotropia or convergent), outward toward the ear (exotropia or divergent), downward (hypotropia) or upward (hypertropia).
What causes Strabismus?
The exact cause of the eye misalignment that leads to strabismus is not known yet. However, strabismus is certainly more common in families with a history of the disorder. Six eye muscles control an eye movement is attached to the outside of each eye.
To focus both eyes on a single target, all eye muscles must work together with the corresponding muscles of the opposite eye. The brain coordinates these eye muscles.
It is important to understand that it is generally not just one eye that is deviated, but rather, the eyes are misaligned in relation to one another.
In essence, both eyes are usually at fault, although one eye may appear to be the “crooked’ one.
Strabismus can be caused by issues regarding the eye muscles, with the nerves that control the eye muscles or with the brain, where the signals for vision are processed.
Strabismus can accompany some illnesses such as high blood pressure, multiple sclerosis, myasthenia gravis, or thyroid disorders.
Signs & Symptoms of Strabismus
Strabismus can mostly be recognized by a casual observer. In general, most cases of strabismus are first seen by a parent or the child’s pediatrician before an ophthalmologist.
Children should be monitored closely during infancy and the preschool years to detect potential eye problems, particularly if a relative has strabismus.
Symptoms of strabismus include:
- Eyes which looks misaligned
- Eyes which did not appear to move together
- Blinking or squinting of eye, especially in bright sunlight
- Tilting the head to look at things
- Faulty depth perception
- Double vision
Treatment of Strabismus
The treatment goal for strabismus is to preserve vision, to straighten the eyes, and to restore 3-dimensional vision. Treatments differentiate, depending on the type and cause of strabismus. If your child’s strabismus has caused amblyopia, treatment will aim at bringing the vision up to normal in the “lazy” eye first.
- Glasses may help straighten the eyes
- A small patch can be worn over the preferred eye to force the child to use the weaker or suppressed eye
- Eye drops are used to temporarily blur the vision of the preferred eye for the same purpose. Exercises may be prescribed to strengthen specific eye muscles
This can be done by forcing a child to use the weaker eye and improve sight by reinforcing the connection between the eye and the brain.
Surgery on the eye muscles can be necessary, especially when glasses are not enough to straighten the eyes. It’s important to understand that strabismus surgery does not resolve amblyopia.
However, the most of the children with strabismus will eventually require strabismus surgery to better align the eyes.
In some cases, surgery can be avoided by using a relatively new technique in which a drug botulinum is injected into one or more eye muscles to temporarily paralyze the muscle.