It all starts with an eye exam!
Strabismus is a condition identified as two eyes that fail to to maintain proper alignment and work together. If you have strabismus, you may notice that one eye will focus directly on the object you are viewing, while the other eye is misaligned and pointing inward (esotropia, “crossed eyes” or “cross-eyed”), outward (exotropia or “wall-eyed”), upward (hypertropia) or downward (hypotropia).
Strabismus can be intermittent or constant, depending on the severity. This misalignment also may always affect the same eye (unilateral strabismus), or could present in the form of two eyes that take turns being misaligned (alternating strabismus). To prevent double vision from congenital and early childhood strabismus, the brain ignores the visual input from the misaligned eye, which typically leads to amblyopia or “lazy eye” in that eye.
Strabismus Symptoms and Signs
The primary sign of strabismus is a visible misalignment of the eyes, with one eye turning in, out, up, down or at an oblique angle. Corneal light reflex (Hirschberg) test is a screening test for strabismus. This test allows the doctor to evaluate your eyes and identify how they align based on the location of reflections of light shined at the eyes.
When the misalignment of the eyes is obvious, the strabismus is called “large-angle,” which refers 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.
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.
Newborns often have intermittent crossed eyes due to incomplete vision development, but this frequently disappears as the infant grows and the visual system continues to mature. Most types of strabismus, however, do not disappear as a child grows.
Regular children’s eye exams are the best way to detect strabismus. Generally, the earlier strabismus is detected and treated following a child’s eye exam, the more successful the outcome. Without treatment, your child may develop double vision, amblyopia or visual symptoms that could interfere with reading and classroom learning.
What Causes Strabismus?
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.
In most cases an 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.
The earlier strabismus is treated surgically, the more likely it is that the affected eye will develop normal visual acuity and the two eyes will function together properly as a team. Please speak to your Vision Associates eye doctor to learn more about eye alignment treatment options.