Strabismus is a condition in which the eyes are not aligned and point in different directions. This condition affects about 4% of adults.
Strabismus may begin in childhood and persist, reoccur, or become symptomatic in adulthood. Strabismus also can result from certain medical problems. Graves' disease (thyroid eye disease), diabetes, strokes, and trauma are some of the more common conditions that can lead to strabismus. Less common causes are diseases that affect the muscles such as myasthenia gravis, demyelinating diseases such as multiple sclerosis, or brain and orbit tumors. Occasionally strabismus can develop after eye surgery, such as cataract, retinal, refractive or glaucoma surgery.
Adults with strabismus may have double vision, loss of depth perception, confusion between images, eye fatigue, headache and reading difficulty. They often experience psychological or social problems because of the condition, and they may have problems interacting with others or securing employment because of the appearance of their eyes. In some cases an abnormal head posture will be adopted in order to use the eyes together. This can lead to musculoskeletal disorders such as arthritis
Double vision occurs when the eyes are not aligned properly, and each eye sees a different image. Young children will learn to suppress or ignore the image from one eye, however adults are unable to suppress images and therefore have double vision. This can be relieved by closing one eye, wearing a patch or realigning the eyes.
Strabismus can be treated at any age. Occasionally, eye muscle exercises, prism eyeglasses, or botulinum toxin injections can improve certain types of strabismus if the misalignment is slight. Eye muscle exercises may be helpful in treating special problems such as convergence insufficiency, where the eyes are misaligned only for near work such as reading. Glasses with prism are most useful forcorrecting small deviations. Botulinum is a drug that can be injected into the muscle to temporarily paralyze the eye muscle. Its effect lasts afew months and in some cases can improve alignment and appearance.
Often surgery is required. Surgery is done on an outpatient basis and in some cases can be performed with a local anesthetic. Strabismus surgery involves loosening, tightening, or repositioning the muscles to align the eyes. An adjustable suture may be used to fine-tune the end result. Your eye doctor can recommend treatment options.