What is Strabismus?

Have you ever wondered why some people have misaligned eyes? The condition is collectively called strabismus and it is classified into several types.

In normal eyes, the external eye muscles or extraocular muscles are supposed to work perfectly for proper position, function, neurological control, and binocular vision. People with strabismus have anatomical or neurological problems that interfere with one of those.

Types of Strabismus

The type of misalignment of the eyes is classified based on the direction of the misalignment. Below are the most common types of strabismus.

Esotropia

This is described by the turning-in of one or both the eyes and is sometimes called crossed eyes. Some newborns may exhibit this symptom, but they usually go away after a while. But if the misalignment does not correct itself by the time the baby is 4 months old or the misalignment is significant, the child should be taken to an ophthalmologist for proper diagnosis. Esotropia can also be a symptom of another eye condition, neurological condition, thyroid eye diseases, stroke, and others.

If left untreated, the child will frequently experience double vision, amblyopia, and decrease in the binocular vision. Although the condition can run in families, a baby has a higher risk of developing esotropia if he/she is born premature, or there is a history of systemic disorders, neurological problems, and other genetic disorders in the family. Esotropia can be treated by addressing the cause of the problem. This means that ocular alignment, diplopia, and amblyopia should be addressed using spectacles, surgery, and Botox injections.

Exotropia

This type of strabismus is the opposite of esotropia. Exotropia is the turning outward of one or both eyes and is most noticeable if the child is daydreaming or is tired or looking at a distance. Intermitted exotropia is harmless as long as it resolves itself, but if it happens frequently, the child should be taken to an ophthalmologist. Usually, the child is unaware that one eye has drifted outwards and experience no changes in the vision, although some describe blurry or double vision.

One common symptom is that the child will close or squint one eye when they focus on bright lights, which means that it can be difficult for them to use both eyes at the same time. Other than possible genetic abnormalities and eye conditions, exotropia is not caused by any external factor or activity. This is usually treated using glasses or surgery to realign the eyes if the symptoms affect everyday activities.

Hypertropia and Hypotropia

Hypertropia is the turning upwards or the eye, while hypotropia is the turning downwards of the eye. It does not cause pain and other symptoms, but the child will experience double vision, eye strain, and headaches from time to time. One common sign is that unconsciously they will tilt the head to one side to get better vision. However, these types of strabismus may be a symptom of other conditions such as Brown syndrome, fourth cranial nerve palsy, and Duane syndrome.