Strabismus is a misalignment of the eyes where the two eyes are pointed in different directions. Though it is a common condition which affects 4% of children, it may appear later in life. One eye may be directed straight ahead while the other eye is turned inward, outward, upward or downward.
There are six eye muscles attached to the outside of each eye. In order to line up and focus both eyes on target, all eye muscles must be balanced and working together. When the eye muscles do not work together then misalignment of the eyes or strabismus results.
Normal alignment of both eyes during childhood allows good vision to develop in each eye. Strabismus may cause reduced vision or amblyopia. Amblyopia occurs in approximately one-half of children with strabismus. Amblyopia can often be reversed by patching the better seeing eye in order to strengthen the vision of the weaker eye. Treatment must be started at the earliest possible age to prevent permanent loss of vision.
The two most common forms of strabismus are esotropia,where an eye turns in and exotropia, where an eye turns out.
Esotropia is the most common type of strabismus in infants. Esotropia when present at birth or within the first six months of life usually requires surgery for correction. Esotropia in children older than two years is commonly due to a need for glasses. These patients usually respond to glasses therapy alone. Exotropia most commonly occurs when a child focuses at distant objects. This may occur only intermittently when the child is daydreaming or tired. Parents may notice the child squinting one eye in bright sunlight. Glasses may reduce the amount of turning in some cases however surgery is needed.
Children should be examined by their family doctor, pediatrician or ophthalmologist during infancy and preschool in order to detect any potential eye problem. It is never too early to have a child's eyes examined. Fortunately, an ophthalmologist can test even a newborn infant's eyes. After a complete eye examination including a detailed study of the inner structure of the eye, an ophthalmologist can recommend appropriate optical, medical or surgical therapy.
The goals of treatment are to preserve vision, straighten the eyes and restore binocular vision.