by Scott Silverman, MD
Fellowship trained Pediatric Ophthalmologist

Definitions
Vision problems are common in children. Early recognition and treatment are the keys to preventing permanent visual impairment. Let us begin by defining two important terms: strabismus and amblyopia.

Strabismus and amblyopia are common, each occurring in 4 of 100 children. The risk of these conditions is much higher with a family history of eye problems.

Dispelling the myths
Let me dispel two common misconceptions about visual development in children:

Children do not outgrow crossing
Many parents have been told that their child would outgrow crossing of the eyes. This is simply not true. It is normal for the eyes of infants up to four months of age to cross or drift out. After this time, however, eyes should be straight at all times. If you see drifting of the eyes after four months of age, bring this to the attention of your pediatrician or eye doctor.

Not all lazy eyes are crossed
Some children with amblyopia have crossed eyes while others have perfectly straight eyes. In children with crossed eyes, one eye is "turned off" by the brain to avoid double vision. The ignored eye fails to develop fully, and amblyopia develops. In children with straight eyes, amblyopia can develop due to a droopy eyelid, a cloudiness in the front of the eye, or not wearing needed eye glasses. These children will show no obvious sign of a vision problem, emphasizing the need for early testing of vision. The eye with the vision problem is "turned off" by the brain and does not fully develop. Amblyopia responds well to treatment before 7 years of age but may be untreatable if diagnosed later.

Detection and Diagnosis
Strabismus is usually recognized by parents as a crossing or drifting out of one or both eyes. The drifting may be constant or intermittent. An exam by your pediatrician or eye doctor can confirm whether strabismus is present.

Amblyopia can be more difficult to detect. Many children with amblyopia show no obvious sign of a vision problem since they use the normal eye to see and ignore the other. Early vision testing by your pediatrician or eye doctor is essential. Amblyopia is detected during an eye exam by finding a difference in the vision between the two eyes.

Treatment
Fortunately, most children with amblyopia and strabismus can be cured. Early recognition and treatment are the keys to preventing permanent visual impairment.

Treatment of Amblyopia
In order to correct amblyopia, children must be forced to use the lazy eye. The brain must be conditioned to pay attention to images from the lazy eye. This is usually accomplished by patching or covering the good eye during waking hours, often for weeks or months. The patching regimen is usually started as close to full time as possible. As the vision begins to improve, the patching may be reduced. Part time patching is usually needed until 9 years of age. Patching can be a trying experience for the family but the vision gained will benefit the child for his or her entire life. The patches are designed to block out as much light as possible. The most effective patches are large "Band-Aid" types that completely cover the eye. Specially designed cloth patches that snugly fit over one lens of a pair of glasses can also be effective.

Treatment of Strabismus

Many children with amblyopia also have strabismus, misalignment of the eyes. In children with both amblyopia and strabismus, the amblyopia must be treated first. Once the vision in the amblyopic eye is optimized, the strabismus can be corrected. Strabismus can sometimes be cured with glasses, but often requires eye muscle surgery.

There is a common misconception that strabismus is difficult or impossible to correct. Actually, treatment for this condition is safe and effective. The eye is not removed from the orbit, nor are any lasers used during eye muscle surgery. While under general anesthesia, the eye muscles are repositioned to straighten the eyes. Although some patients may require more than one surgery over time, the surgery is safe and effective and takes less than an hour to complete. Children do not need to stay overnight in the hospital nor are any eye patches necessary after surgery. Recovery time is rapid, children are generally playing and back to school within a couple days.