Diagnostic Criteria
Duane syndrome is a strabismus condition clinically characterized by congenital non-progressive limited horizontal eye movement accompanied by globe retraction which results in narrowing of the palpebral fissure. The diagnosis of Duane syndrome is based on clinical findings and classified into three types . Most affected individuals with Duane syndrome have isolated Duane syndrome (i.e., they do not have other detected congenital anomalies). Other individuals fall into well-defined syndromic diagnoses (see and ). However, many individuals with Duane syndrome have non-ocular findings that are not classified as a particular syndrome; they are included in this review for completeness. The vast majority of individuals with isolated Duane syndrome represent simplex cases (i.e., a single occurrence in a family). A positive family history showing autosomal dominant inheritance is apparent for approximately 10% of affected individuals . Suggestive Findings Duane syndrome, a congenital, non-progressive eye movement disorder, should be suspected in individuals who present with the following features: • Congenital limited horizontal eye movement with impairment of abduction and/or adduction • Globe retraction (co-contraction) accompanied by narrowing of the palpebral fissure (i.e., reduced distance between the upper and lower eyelids) on adduction. Note: Adduction is movement of the globe toward the midline (the nose); abduction is movement of the globe toward the ear, away ("abducted") from the midline. Establishing the Diagnosis Clinical findings. The diagnosis of Duane syndrome is established in a proband typically by an ophthalmologist by detection of the specific clinical findings of limited abduction and/or adduction in association with globe retraction on adduction. Individuals can usually be categorized within the three types detailed below, though there may be some overlap among these categories. Table 1. Clinical Findings: Comparison of Duane Syndrome Types I-III
