Strabismus

What Is Strabismus?

Strabismus is when the eyes do not remain aligned, or do not point at the same spot, while looking straight ahead or to the sides. The misalignment can occur in one eye or in both eyes.

What Is Latent Strabismus?

This is when eye misalignment is not constant but appears only from time to time.

Why Does Strabismus Occur?

Each eye has 6 muscles that move it, along with the nerves that control these muscles. The exact cause of strabismus is not known. However, it is thought to result from a mismatch between the eye muscles and their nerves. Neurological problems, particularly nerve palsies in adults, can sometimes cause strabismus as well.

Genetic factors are also important in strabismus. People who have relatives with strabismus have a higher likelihood of developing it themselves.

What Are the Symptoms of Strabismus?

The primary symptom of strabismus is that the eyes do not remain aligned when looking straight ahead or in other directions (right, left, up, down).

Strabismus patients often also have a high degree of refractive error and amblyopia (lazy eye). As a result, many of these patients see less well than normal. In addition, because the eyes are not used together, three-dimensional vision and depth perception are also weaker in these patients.

Patients with latent strabismus may also complain of difficulty reading at near range, headache, and watery eyes.

How Is Strabismus Treated?

The first step in treating strabismus patients is eyeglass treatment. Patients with esotropia (inward eye turn) in particular are given eyeglasses with as high a power as possible, based on measurement with dilating drops. In the second stage, amblyopia, if present, is corrected. For this purpose, the better-seeing eye is patched, and the weaker eye is made to work through near activities. In some cases of strabismus, exercises that work the eye muscles may be prescribed. In cases of strabismus that do not improve with these treatments, surgery is performed.

What Is the Effect of Eyeglasses on Strabismus?

Eyeglasses are the first treatment used for strabismus patients. In children with esotropia and hyperopia in particular, eyeglasses can correct the misalignment. However, it should be kept in mind that the misalignment will return once the eyeglasses are removed. This is an expected outcome and does not mean the eyeglasses are not working as treatment.

In addition, in some patients strabismus is only partially corrected with eyeglasses, and surgery is needed for the remaining portion. In these patients too, the misalignment is fully corrected with eyeglasses after surgery. However, when the eyeglasses are removed, some misalignment persists, which is an expected outcome.

Will My Child Have to Wear Eyeglasses Forever?

Refractive errors, particularly hyperopia, are more common in strabismus patients. In a significant proportion of children with hyperopia, the diopter decreases over time. However, there are also patients whose diopter does not decrease and who must continue wearing a high power correction.

How Is Strabismus Surgery Performed?

Depending on the case, strabismus surgery is performed on one eye or both eyes. During surgery, the muscles that move the eyes are weakened or strengthened. Depending on the size of the misalignment angle, this is done on one or two muscles. The surgery takes about 30 minutes. With good planning, its success rate is above 90%.

When Should I Have Strabismus Surgery?

The answer to this question is not the same for every case of strabismus. However, as a general rule, once amblyopia has been corrected, strabismus surgery should be performed without much delay. This is because amblyopia treatment ensures that each eye sees well individually. However, three-dimensional vision and depth perception do not develop until the strabismus is corrected. The development of three-dimensional vision stops after age 6 to 7. For this reason, strabismus surgery should be performed as soon as the amblyopia has been corrected.

At the same time, having surgery too early, before the amblyopia has been corrected, is not advisable either, since surgeries performed before amblyopia is corrected have a lower chance of success.