Duane's retraction syndrome, a case series from Iran

Purpose: To determine the relative prevalence of Duane's retraction syndrome (DRS) in a population of Iranian strabismus cases and to describe the clinical features. Methods: Retrospectively, a population of 7,349 strabismus cases visited during 2000-2003 were evaluated for the diagnosis of DRS. Data regarding onset (noticed age), type, head turn, primary position deviation, narrowing of the palpebral fissure, leash phenomenon, refractive error, amblyopia, and history of surgery were collected. Chi-square test and Student's t-test were used. Results: About 125 DRS cases were diagnosed (prevalence: 1.7%). The noticed age of the syndrome was at birth in 35.6%, during infancy in 25.4%, or childhood in 39.0%; the age at referral ranged from 3.5 months to 65.0 (median: 10.0) years. The female/male and left/right eye involvement ratios were 3:2 and 3.5:1, respectively. The syndrome was of type I in 87.0%, II in 6.5%, and III in 5.7%; 7.2% were bilateral. Horizontal deviations existed in 76.0% and vertical deviations in 12.8%. 26.8% had different degrees of amblyopia. Leash phenomenon was detected in 37.6% of cases. Head turn, primary position deviation (without turn), and orthophoria were observed in 71.2%, 13.6%, and 15.2%. Surgery had been performed in 71.2% of the cases. Vertical deviations and leash phenomenon were more common in types II and III and hypermetropia in type I (P values: 0.036, <0.001, and 0.025, respectively). Conclusion: Basic features of our series seem to be comparable with previous reports. The incidences of bilateral involvement and type III syndrome were lower. The proportion of cases with head turn was higher and surgery was performed more frequently.