Exotropia is a type of strabismus or squint; a form of ocular misalignment where the visual axes diverge inappropriately. In exotropia one or both eyes start to drift away from the point needed to focus on in order to produce a sharp image of the object. When someone's one eye or both eyes drift away, the brain is unable to form a single image.
The exact reasons causing exotropia are not yet known. The six muscles that control eye movement must work in coordination so that brain can form a single image of the object. There are four muscles for up and down movement of the eye, while, two are for the control of side to side movement. When one or more of these muscles doesn't work properly, for some reason, strabismus may occur. An exotropia occurs when the lateral rectus muscles exert more force on one side of the eye; this pulls the eye in an outward direction. Outward eye deviation is the most common type of exotropia and is known as intermittent exotropia.
Patients suffering from exotropia may experience a double vision effect, which affects their everyday activities, such as driving and reading. Exotropia can also interfere with other activities, like sports, which require a streamline of gazing positions. In order to focus on things, those suffering from exotropia have to adjust their head position in some way other than normal. Over time, the associated head position can lead to secondary neck pain. The divergence of eyes can also have some social implication like the stigma attached or pity.
An estimate tells that roughly one percent of the general population is affected by exotropia. Exotropia is not gender related. It has almost equal amount of sufferers from both the genders, although, exotropia is more common in children.
Children, very often, do not understand what exactly is wrong with their eyes or vision so parents should check for if there’s anything abnormal with their child’s way of looking at things. When children experience double vision due to exotropia, they close one eye and use only one eye for seeing. If it happens repeatedly, parents must make sure of there are any signs for strabismus or exotropia. If not exotropia is not treated properly, it may lead to lose the binocular vision.
Doctors might use eye glasses, eye related exercises, or prismatic correction to fix exotropia. In some case eye muscle surgery is required to treat exotropia depending on the eye examination results. If a surgery is required to be done on a child then it is preferred to perform it before their school age.
Keywords: Exotropia, Strabismus, eye, eye movement, divergence.