Strabismus is a condition in which the eyes do not align with each other. In other words, one eye turns in a direction that is different from the other eye.
Under normal circumstances, the six muscles that control eye movement work together and point both eyes at the same direction. Patients with strabismus have problems with controlling eye movement and cannot maintain normal ocular alignment (eye position).
Strabismus can be categorized depending on the direction of the poorly aligned eye:
There are several forms of strabismus. The three most common are:
Adults may also experience strabismus. Most commonly, ocular misalignment in adults is due to stroke, but it can also occur from physical trauma or from childhood strabismus that was not previously treated or has relapsed or progressed. Strabismus in adults can be treated in a variety of ways, such as observation, patching, the use of prism on glasses and strabismus surgery.
It is estimated that 4% of the population have strabismus.
Most strabismus results from an abnormality of neuromuscular control of eye movement. Our understanding of these control centers in the brain continues to evolve. Less commonly, there is a problem with the actualeyemuscle. Strabismus is often inherited, with about 30 percent of children with strabismus having a family member with a similar problem.
Other conditions associated with strabismus include:
By the age of 3 to 4 months, an infant’s eyes should be able to focus on small objects, and the eyes should be straight and well-aligned. A 6-month-old infant should be able to focus on objects both near and far.
Strabismus usually appears in infants and young children, and most often by the time a child is 3 years old. However, older children and even adults can develop strabismus. The sudden appearance of strabismus, especially with double vision, in an older child or adult could indicate a more serious neurologic disorder. If this happens, call your ophthalmologist immediately.
A condition called pseudostrabismus (false strabismus) can make it appear that a baby has crossed eyes when in fact the eyes are aiming in the same direction. Pseudostrabismus can be caused by extra skin covering the inner corners of the eyes and/or a flat nasal bridge.
Anyone older than four months of age the agewho appears to have strabismus should undergo a full ophthalmological examination by a pediatric ophthalmologist, with extra time spent examining how the eyes focus and move. The examination may include the following:
Treatment options include the following:
Some believe that children will overcome strabismus or that it will improve on its own. In fact, it can get worse if not treated.
If the eyes are not properly aligned, the following may result:
It is also possible that by not diagnosing strabismus, a serious problem (such as a brain tumor that causes the condition) can be overlooked.
The patient will need to see the Paediatric Ophthalmologist for follow-up to see if the patient has responded to treatments, and to make adjustments, if necessary.
In the case of children with strabismus, if the condition is caught in time and properly treated, it can result in excellent vision and depth perception and can protect against loss of vision.