Strabismus is a condition in which the eyes are misaligned and point in different directions. One eye looks straight ahead while the other turns inward, outward, upward or downward. This misalignment may be constant or intermittent.
Strabismus is common among children, appearing in about 4% of all children. It can also occur as an adult and may run in families.
With normal vision, both eyes aim at the very same spot. The brain then fuses these two images into one three-dimensional image thus giving us depth-perception. When one eye turns, two different images are sent to the brain. If the child is young enough, the brain ignores the image from the turned eye. This can cause amblyopia ("lazy eye") and loss of depth perception. In an adult, this usually causes double vision.
Amblyopia treatment is covered on another page and should be viewed since it will very often go hand in hand with strabismus.
Strabismus can be diagnosed during the office examination. Often, the eyes will only appear to be crossed. This condition is called pseudostrabismus. Dr. Kronwith will be able to differentiate between pseudostrabismus and true strabismus. Once true strabismus is diagnosed, it is imperative to understand that a child will not outgrow it. It must be treated.
The treatment of strabismus is to preserve vision, straighten the eye and hopefully restore binocular (two-eyed) vision.
In some cases glasses can be prescribed for your child which will keep the eyes straight. Other treatments may involve surgery on the eye muscles. Patching of the stronger eye to improve amblyopia is often necessary.
The most common types of strabismus are esotropia and exotropia.
ESOTROPIA is where the eye turns inward and is the most common type of strabismus in infants. These children do not use their eyes together and often early surgery is necessary to align them. In children who develop esotropia after 6 months of age or later in childhood, eyeglasses may straighten the eyes. These glasses may be required for the child's entire life but many times are no longer needed by the early teens.
EXOTROPIA is when an eye turns out. This type is often intermittent, occurring when the child is tired, sick or daydreaming. Parents may also note that the child squints in the sunlight. Although glasses and exercises may help control exotropia, surgery is often necessary.
Surgery for strabismus is done as an outpatient procedure, usually lasting from 1 to 2 hours. Certain muscles of the eye are located, cut and sewn back on the eye at different locations in order to change how strongly they move the eye. The eyeball itself is never removed during the surgery. Surgery will require general anesthesia. Recovery time is rapid and normal activities are usually restarted in a few days. After surgery, glasses may still be required to keep the eyes straight. In about 15% of cases, further surgery may be needed at some point in the future.
As with all surgery, eye muscle surgery has some risks and the doctor will go over them with you in detail. Having said that, strabismus surgery is usually an extremely safe and effective treatment for eye misalignment. It is not, however, a substitute for glasses or amblyopia therapy.