Bilateral Medial Rectus Recession Posterior to the Functional Equator in Esotropia Over 40 Prism Diopters

PURPOSE: To investigate bilateral medial rectus recession by considering functional equator as a surgical guideline in esotropia over 40 prism diopters (PD). METHODS: Forty-one patients who underwent bilateral medial rectus recession, and were followed-up for more than 12 months, were reviewed. The success rate was compared between group 1 and group 2, which were divided to recession site from the functional equator posterior, and also between the hyperopia group and myopia group according to refraction. RESULTS: According to preoperative deviation angle, 21 patients underwent recession to less than 10 mm posterior to the functional equator (group 1) and 20 patients had recession to 1.5 mm to 2.0 mm posterior to the functional equator (group 2). No significant difference in success rate between group 1 (71.4%) and group 2 (75.0%) was detected at the last follow-up. When divided into a hyperopia group (26 patients) and myopia group (15 patients), the success rate in the myopia group was higher than in the hyperopia group, as observed at the last follow-up, but the difference was not significant. There was 1 case of overcorrection in each group. CONCLUSIONS: A successful outcome was achieved in 30 patients (73.2%), and overcorrection in 2 patients (4.9%) when recessed to 2.0 mm posterior to functional posterior in esotropia over 40PD.

Clinical Analysis of Large Recession of Bimedial Rectus Muscles in Esotropia

Nineteen patients with large angle esotropia who have undergone bimedial rectus recession ranging from 7 to 8 millimeters were evaluated. We retrospectively reviewed preoperative and postoperative visual acuity, deviation, ocular motility, fusion, stereoacuity in all patients. The mean preoperative deviation was 76 prism diopters, ranging from 65 to 95 prism diopters and the mean postoperative follow up interval was 55.6 months, ranging from 26 to 80 months. The overall successful rate(horizontal orthotropia within+/-10 prism diopters) was 42.1%(8/19). The rate of undercorrection was 47.7%(9/19) and the rate of delayed consecutive exotropia was 10.5%(2/19). Fusion at near was found in 36.8%(7/19) and stereopsos of 200 seconds or better was found in 15.8%(3/19) of patients postoperatively.We observed no limitation of adduction or convergence. If reoperation was necessary, there still remain other untouched horizontal muscles on which to operate.Therefore, 7 to 8 millimeter medical rectus recession is the first effective procedure for the correction of large angle esotropia with deviations of more than 65 prism diopters.