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Duane Syndrome is a congenital form of strabismus characterized by horizontal eye movement limitation, globe retraction with palpebral fissure narrowing in attempted adduction. This condition results from paradoxical innervation of rectus lateral muscle. The syndrome is classified in three types based on the presence of a defect in adduction, abduction or both. The incidence is approximately 1% of the total cases of strabismus. Duane syndrome can be isolated or associated with ocular anomalies (heterochromia, iris dysplasia, colobomas, Marcus-Gunn phenomenon...), and systemic anomalies (Goldenhar`s syndrome, Klippel-Feil syndrome, sensory neural hearing loss.). Most cases are sporadic, however familial occurrence with dominant autosomal inheritance pattern has been reported. Duane syndrome has been linked to five loci and a first causative gene, SALL4, has been identified. The currently proposed etiologic mechanism is that Duane syndrome results from an innervational disturbance of brain stem origin in which the lateral rectus muscle is partially innervated by branches of the oculomotor nerve. When required, surgical procedures are used to improve the primary gaze alignment, face turn and postural position, but the results are limited. |