What Is Strabismus?

Though there are many eye disorders and diseases, few are more noticeable than strabismus. Some may confuse it as a “lazy eye”, however it is a completely different disease that comes in many forms. It occurs when one of the eyes is misaligned, at any angle, and may or may not cause visual impairment. There are several different types and variations of strabismus, and it should be diagnosed by an eye doctor. If done early, such as in infancy, it can possibly be reversed.

What Are The Different Types Of Strabismus?

There are several variations of strabismus. Some deal with the position of the eye, while others deal with the frequency of the condition.

Strabismus can occur all the time, referred to as constant. Or, the misalignment can occur spontaneously and at random intervals, known as intermittent. Along with the timing of the misalignment, strabismus can also be categorized based on the position of the eye. In the disorder, the eye can move in any direction. When it moves inward, it is known as esotropia. When it moves outward, it is called exotropia.

A final classification is determined by the angle of the misalignment. If the eye is only slightly misaligned, it is small-angle strabismus. If it is severely misaligned, it is large-angle strabismus. The angle of the misalignment determines whether the strabismus negatively affects vision or if it is simply a physical misalignment. Finally, strabismus can occur in one eye, both, or change between them.

What Causes Strabismus In Children?

Strabismus, of any kind, is related to the six muscles that control the movement of the eye. In the disease, the muscles are not well coordinated and do not keep the eye in the proper position. Children typically are either born with strabismus or develop the condition between the ages of 1 to 4. There is a genetic component to the condition, meaning that parents can pass it down to their children. However, it is not strictly genetic, and a child can have it even if the parents don’t.

What Causes Strabismus In Adults

For adults with no history of strabismus in childhood, it is often the result of a traumatic brain injury that damages the nerves that control the eye muscles. However, it can also be attributed to systemic diseases like diabetes, thyroid disease, or myasthenia gravis. When strabismus is developed in adulthood, it is very difficult to reverse. However, surgery has a possibility of fixing the condition.

How Is Strabismus Diagnosed?

Strabismus is diagnosed during an eye exam. For this reason, individuals who notice or are told that their eye appears to be misaligned should visit the eye doctor immediately. Children should begin going to the eye doctor around age 3 and should also have their vision checked regularly by the pediatrician in a basic vision assessment. Taking these measures can help catch strabismus early and get the child treatment to help reverse or manage the condition. Catching the condition early can lead to better treatment outcomes and mitigates the negative affects that strabismus can have on vision.

What Are The Treatments For Strabismus?

Since strabismus can come in so many forms, treatment for it depends on what form a person is suffering from. However, in most cases, surgery is the best option. For a strabismus surgery, an ophthalmologist who specializes in eye surgery will not remove the eyeball from the socket, but instead make a small incision that allows him/her to reach the six inner eye muscles. From there, the surgeon will detach and reattach the muscle that is causing the misalignment. This surgery is generally successful; however, it may take more than one surgery to fully correct the misalignment. In some cases, a slight degree of strabismus may remain if not treated until late adulthood, long after the condition appeared. This is why it is vitally important to receive treatment early. If done early enough, the strabismus surgery can be highly effective and return normal vision by allowing the eyes to work correctly as a team.

Some risks associated with strabismus surgery are: unsatisfactory eye alignment, a change in vision (ie. blurred vision, nearsightedness, farsightedness), or double vision. The risk for muscle detachment and scarring is also possible.

For children, or those with intermittent strabismus, another treatment option is vision therapy. This is very effective in specific cases, such as convergence insufficiency, a type of intermittent exotropia. Vision therapy is the preferred method of treatment if possible for children and those with mild strabismus because there is less risk associated with it than with surgery.

Is Strabismus The Same Thing As A Lazy Eye?

In short, no. Lazy eye (amblyopia) is a condition that can be caused by strabismus but is not the same disease. When one eye has poor vision in childhood, such as when strabismus makes it difficult to see or focus, the brain starts to ignore the bad eye. By focusing only on vision signals from the good eye, the person loses depth perception. Additionally, their bad eye will get worse and move sporadically since the brain is not relying on it for vision. Avoiding this problem is possible if it is properly diagnosed and treated early on. For example, children could be given an eye patch to wear over their good eye, forcing the brain to rely on the bad eye, therefore strengthening it.

Does Strabismus Cause Blurry Vision?

The effects of strabismus on vision are dependent on what variation of the condition a patient has. For example, in constant strabismus, the brain ignores signals coming from the affected eye. While this results in a lack of depth perception, the person should still be able to see clearly thanks to the good eye. However, patients with intermittent strabismus won’t adjust as easily to ignoring the vision signals from the affected eye. This can leave them with blurred vision or trouble focusing on things—either far away or near to their face. To determine if vision problems are being caused by strabismus or by another factor, a trip to the eye doctor is necessary.