Strabismus is a condition in which a person's eyes are not aligned. It is commonly called "crossed eyes" in the United States. Between 4 and 5% of people have strabismus. The condition usually develops in toddlers younger than 3. While one eye focuses, the child's other eye may turn inward or outward, up or down. If a child with strabismus stops using the affected eye, she may develop amblyopia (lazy eye), which can lead to vision loss.
Children and babies often cross their eyes, especially when they're tired. An obvious sign of strabismus is if your child has one eye that doesn't look straight ahead. A child with strabismus may turn her head or close one eye completely to look at you. Other signs of strabismus include:
- Eyes that cross or are misaligned
- Eyes that don't move together (uncoordinated)
- Double vision
- Loss of vision or depth perception
Tests and Diagnosis
For most kids, the cause of strabismus is unknown, although more than half the time it is present either at, or shortly after, birth. This is known as congenital strabismus. Strabismus is almost always due to problems with neuromuscular control rather than muscle strength.
A child's ability to focus, as well as her depth perception and eye muscle coordination all develop by 6 months of age. By 9 months, the vision system is set. Any disruption to the system before approximately 4 years may result in strabismus.
Strabismus can be hard to detect in some children, so all infants should have an eye exam by their first birthday. Signs of strabismus include crossed or misaligned eyes, double vision or a loss of depth perception.
Strabismus is also associated with several disorders, including:
- Cerebral palsy
- Down syndrome
- Congenital rubella
- Traumatic brain injury
- Apert syndrome
- Hemangioma (benign tumors near the eye during infancy)
- Noonan syndrome (NS)
- Intercontinental pigmenti (IP)
- Prader-Willi syndrome (P.W.S.)
- Retinopathy of prematurity
- Retinoblastoma (Rb)
- Edwards syndrome (Trisomy 18)
An ophthalmologist will begin the diagnosis by asking you about your child's medical history. Questions may include "At what age did you first notice your child's misalignment?" and "Do you have a family history of congenital eye problems?" He will then perform a physical exam to make sure there isn't an underlying eye disease that's causing the disorder.
Tests to detect strabismus include:
- Corneal reflex
- Cover test (measures the amount of deviation between the eyes)
- Retinal exam
- Visual acuity test
- A neurological exam
If your child has amblyopia, he will need to be treated for that first. “Patching” is usually used to treat amblyopia. Your child's strong eye is covered, which over time allows the weak one to work harder. Once the amblyopia has been dealt with, treatment can begin on the strabismus. Treatments for strabismus include prescription lenses (if necessary) or, if the cause is weak eye muscles, surgery.
Eye muscle repair surgery
Eye muscle repair corrects misaligned eyes that result from muscle problems. Your child will receive general anesthesia before the procedure. The surgeon may remove a section of muscle or tendon to make a muscle stronger. To weaken a muscle, the doctor will reattach it toward the back of the eye (recession). The younger your child is when the surgery is done, the better her chance of achieving normal or near-normal vision. Some children may have to wear glasses even after surgery.
For more information about strabismus, please visit the following sites:
This page offers brief explanations of the different types of strabismus.
American Association for Pediatric Ophthalmology and Strabismus
An overview of causes, symptoms and treatments for strabismus:
U.S. National Library of Medicine
This page has information about eye-muscle repair surgery.
U.S. National Library of Medicine
Here are answers to a number of questions about childhood strabismus:
What is strabismus?
Strabismus is any misalignment of the eyes. It is often known as “crossed eyes” in the United States.
How common is strabismus?
Strabismus is very common. Between 4 and 5% of people in the U.S. have the condition.
What causes strabismus?
Most cases of strabismus are present or develop in otherwise normally developed kids shortly after birth. Children with brain disorders such as cerebral palsy and Down syndrome are at a greater risk for strabismus.
How is strabismus diagnosed?
An ophthalmologist will ask you when you first noticed the misalignment, and about your family history. A physical exam and eye tests can detect strabismus in children.
What are the treatments for pediatric ocular trauma?
Kids with amblyopia (lazy eye) in conjunction with the strabismus must be treated for that condition first. Treatments for strabismus include corrective lenses or, in some cases, surgery.
What is the prognosis for children with strabismus?
The younger a child is when treated for strabismus, the better the outcome. Many children who have been treated for strabismus will need glasses, but otherwise lead normal, healthy lives.