Duane's syndrome is a congenital muscle disorder of the eyes. Generally, there is a miswiring of the nerves that supply the ocular muscles. Based on embryology, the defect in Duane's syndrome most likely occurs around the sixth week of in utero development. The condition is present at birth.
In Duane's syndrome Type 1, the most common form, the nerve that supplies the lateral rectus does not develop properly. This results in the eye not being able to move correctly towards the ear. Problems associated with Duane's syndrome include: strabismus, anomalous head position, upshoots or downshoots, eyelid fissure narrowing, and amblyopia. Duane's syndrome Type II involves difficulty moving the eye inward and Type III involves difficulty moving the eye both outward and inward. Duane's syndrome may be associated with other eye abnormalities or systemic abnormalities, such as Goldenhar syndrome.
Treatment is focused on reducing upshoots or downshoots, improving eye alignment, and reducing head turns. The goal of surgery is not to return normal function to the abnormal muscle. Unfortunately, the function of the abnormal muscle cannot be restored through surgery. Surgery is generally effective in reducing the degree of head turn and strabismus, but does not restore completely normal function to an abnormal oculomotor system. The impact of surgery may take several weeks to manifest and may not be present in the immediate postoperative period.