Objective: To report the results of bilateral medial rectus muscle recession in improvement of the ocular alignment and motility of patients with unilateral esotropic Duane syndrome.

Methods: All medical files of patients with Duane syndrome seen by the first author between 1997 and 2006 were reviewed. Pre- and postsurgical deviation, angle of abnormal head position, severity of limitation in abduction, severity of globe retraction, and upshoots and downshoots were compared.

Results: Twenty-five patients with unilateral esotropic Duane syndrome (type 1) underwent recession of both medial rectus muscles. Mean age of patients was 9.7 years: male-to-female ratio was 0.67 (10:15). The left eye was involved in 23 of the patients. Mean esotropia decreased from 24.3(Delta) (range, 12(Delta)-50(Delta)) to 1.3(Delta) (range, 0(Delta)-10(Delta)). Mean abnormal head position decreased from 21.4 degrees (range, 15 degrees-35 degrees) to 1 degrees (range, 0 degree-5 degrees). Esotropia and abnormal head position disappeared in 80% of the patients and improved in the remaining. None of the patients developed exotropia. Mean limitation in abduction decreased from -3.8 to -3.3. Globe retraction was eliminated in 14 of the patients and improved in the others. Mild upshoots and downshoots, which were observed in 5 patients, disappeared in 2 and improved in 3 patients.

Conclusions: Bilateral recession of medial rectus muscles has resulted in improvement of deviation, abnormal head position, and globe retraction in patients with unilateral esotropic Duane syndrome.