Dose-effect relationship of bilateral medial Rectus advancement in the treatment of consecutive exotropia

Abstract

This study aims to examine the success rate of this technique and to report the dose–effect relationship for bilateral medial rectus muscle advancement in patients with consecutive exotropia. Methods & Materials A total of 26 patients with consecutive exotropia who had undergone bilateral medial rectus muscle advancement in Nikookari Eye Hospital were enrolled in this interventional study. After 9.7 months follow-up in average, success rate (≤10 prism diopters (PD) esotropia or no deviation) was reported. The dose–effect relationship between millimeters of advancement and the change in deviation at follow-up was also calculated. Results Eleven males (42.3%) and 15 females (57.7%) with a mean age of 19.42±10.10 years at the time of operation were studied. The mean preoperative deviation was 29.50±10.60 PD, which decreased to a mean value of 26.23±13.20 PD at the end of follow-up. At the endpoint a successful outcome was evident in 20 cases (76.9%). There were 8 patients (30.8%) with exotropia, 10 patients (38.5%) with orthotropia, and 8 patients (30.8%) with esotropia. Each 1 mm advancement of the medial rectus muscles led to 5.35 PD correction in deviation at the end of follow-up.