Lateral rectus resection versus medial rectus re-recession for residual esotropia: early results of a randomized clinical trial

Purpose: To compare lateral rectus muscle resection with medial rectus muscle re-recession for patients with residual esotropia. Methods: This randomized controlled clinical trial included 25 patients (mean age, 18.8 +/- 8.7 years) with residual esotropia who were candidates for reoperation. They were randomly assigned into two groups: re-recession group (n = 12), in which the medial rectus muscle was recessed again, and the resection group (n = 13), in which lateral rectus muscle resection was performed. Postoperative deviation <= 10 prism dioptres was considered to be treatment success. Results: The success rate of the re-recession group and the resection group was 67% and 54%, respectively; this difference was not statistically significant. Each 1 mm of medial rectus re-recession and lateral rectus resection corrected 7.5 +/- 1.2 and 2.5 +/- 0.5 prism dioptres of residual esotropia, respectively. In 50% of the re-recession group, mild medial rectus muscle underaction occurred; however, only 16.5% developed an increase in the near point of convergence. Major intraoperative and postoperative complications, including overcorrection and slippage or a lost muscle, did not occur in any of the patients. Conclusions: Medial rectus muscle re-recession can be a substitute for lateral rectus muscle resection in patients with residual esotropia. The resultant underaction of the medial rectus muscle after re-recession is relatively mild and causes no major problems.