Bilateral type III Duane syndrome: a case report.

Purpose: Duane syndrome (DS) belongs to a group of congenital retraction syndromes, the incidence of which varies between 2% and 4% in patients with strabismus. In most cases the damage is unilateral, but it manifests as bilateral in about 20% of cases. According to the classification of Huber, type III DS exhibits a limitation of abduction and adduction.