Strabismus also called as Cross Eye or Wall Eye is a condition that interferes with binocular vision because it prevents a person from directing both eyes simultaneously towards the same fixation point; the eyes do not properly align with each other. It is a vision condition in which a person cannot align both eyes simultaneously under normal conditions. One or both of the eyes may turn in, out, up or down. If you have strabismus, one eye looks directly at the object you are viewing, while the other eye is misaligned inward (esotropia, “crossed eyes” or “cross-eyed”), outward (exotropia or “wall-eyed”), upward (hypertropia) or downward (hypotropia). Strabismus can be constant or intermittent. The misalignment also might always affect the same eye (unilateral strabismus), or the two eyes may take turns being misaligned (alternating strabismus).
Signs & Symptoms- When the misalignment of the eyes is large and obvious, the strabismus is called “large-angle” referring to the angle of deviation between the line of sight of the straight eye and that of the misaligned eye. Less obvious eye turns are called small-angle strabismus. Typically, constant
Large – angle strabismus does not cause symptoms such as eye strain and headaches because there is virtually no attempt by the brain to straighten the eyes. Because of this, large-angle strabismus usually causes severe amblyopia in the turned eye if left untreated. Less noticeable cases of small-angle strabismus are more likely to cause disruptive visual symptoms, especially if the strabismus is intermittent or alternating. In addition to headaches and eye strain, symptoms may include an inability to read comfortably, fatigue when reading and unstable or “jittery” vision. If small-angle strabismus is constant and unilateral, it can lead to significant amblyopia in the misaligned eye. Both large-angle and small-angle strabismus can be psychologically damaging and affect the self-esteem of children and adults with the condition, as it interferes with normal eye contact with others, often causing embarrassment and awkwardness.
Cause – Each eye has six external muscles (called the extraocular muscles) that control eye position and movement. For normal binocular vision, the position, neurological control and functioning of these muscles for both eyes must be coordinated perfectly. Strabismus occurs when there are neurological or anatomical problems that interfere with the control and function of the extraocular muscles. The problem may originate in the muscles themselves, or in the nerves or vision centers in the brain that control binocular vision. Genetics also may play a role: If you or your spouse has strabismus, your children have a greater risk of developing strabismus as well.
a) Surgery- In most cases, the only effective treatment for a constant eye turn is strabismus surgery. The success of strabismus surgery depends on many factors, including the direction and magnitude of the eye turn. In some cases, more than one surgery may be required. The strabismus surgeon can give you more information about this during a pre-surgical consultation. Strabismus surgery also can effectively align the eyes of adults with long-standing strabismus. In many cases of adult strabismus, however, a significant degree of amblyopia may remain even after the affected eye is properly aligned. This is why early treatment of strabismus is so important.
b) Vision Therapy- Sometimes, a strabismus surgeon may recommend a program of vision therapy for a period of time after strabismus surgery to treat amblyopia and minor binocular vision problems that might remain after surgery. In these cases, the term “orthoptics” (“ortho” = straight; “optics” = eyes) rather than “vision therapy” might be used to describe this treatment, which may be provided by an orthoptistworking closely with the surgeon rather than by an optometrist.