What is Strabismus?
Strabismus is the scientific term used to explain an eye turn. In patients with strabismus the eyes will appear to be out of alignment. The condition can be caused by the brain’s inability to coordinate both eyes simultaneously. Children with strabismus may develop additional complications with amblyopia, or “lazy” eye.
Eye turns can be linked to either poor eye coordination and binocular balance, or muscular imbalances. Muscular imbalances denote a mechanical problem with the eye muscles themselves, where there is limited movement, due to restriction e.g. Brown’s Syndrome, or paralysis e.g. nerve palsies.
Types of Strabismus
- The eye can go “in” toward the nose. Esotropia
- It can go “out” from the nose. Exotropia
- It can go “up” or “down”. Hypertropia or Hypotropia
- It can happen part time or all the time. Intermittent
- It can be either eye. Eye turns do not always occur in isolation so often patients may have more than one of the above.
An eye turn is not always constant and may only occur when the child is tired, or when they looking at an object at a certain distance (accommodative problem) or in a certain direction (muscle imbalance). The degree of the turn is not always noticeable, often smaller eye turns cause more symptoms and visual discomfort.
Why Does The Eye Turn
Somewhere early in the child’s development, the brain fails to develop ‘binocularity’ or the ability to use both eyes at the same time. The condition can be congenital or acquired.
‘Congenital eye turns’ mean a baby is born with an eye turn or develops an eye turn within the first 3 to 6 months of life. In most cases the eye turns inwards and surgery is usually required.
‘Acquired eye turns’, particularly esotropia’s are the most common, and develop around the ages of 2 to 6.