Surgical Results of Consecutive Exotropia

Abstract

To determine the success rates of different surgical procedures and the risk factors of surgical failure among patients with consecutive exotropia. Forty patients with exotropia were observed at least 6 weeks after their esotropia surgery. Surgical planning was based on the medial rectus muscle function. Lateral rectus weakening in patients with normal medial rectus function, medial rectus strengthening for patients with limited medial rectus function (-1 to -3), and combined procedure occurred when the correction of each type of surgery was less than the amount of deviation. Postoperatively, patients were divided into success (8 prism diopters [PD] or less) or failure (8 PD or greater) groups. The follow-up period was at least 3 months. The mean preoperative exotropia was 29 ± 13 PD, which was reduced to 7 ± 7 PD postoperatively (P < .001). Successful results were achieved in 31 patients (77.5%), 17 (81%) in lateral rectus weakening, 10 (83%) in medial rectus strengthening, and 4 (57%) in the combined procedure group. More preoperative exodeviation was observed in the failure group compared to the success group (P = .015).The mean dose response was 2.27 ± 0.92 PD/mm in the lateral rectus weakening, 4.25 ± 2.27 PD/mm in the medial rectus strengthening, and 2.31 ± 0.66 PD/mm in the combined procedure groups. If the choice of surgical planning is based on medial rectus function and the amount of exodeviation, satisfactory alignment would be achieved in the majority of patients with consecutive exotropia. The preoperative amount of exodeviation was the only risk factor of surgical failure in the study.