Purpose: To determine which factors are important in the development of secondary exotropia and the incidence of secondary exotropia occurring after a retroequatorial myopexy of the medial rectus muscle with recession in the treatment for partially accommodative esotropia associated with convergence excess.
Methods: In this retrospective study, the patients that underwent retroequatorial myopexy on both medial rectus muscles with recessions for partially accommodative esotropia associated with convergence excess were included. The incidences and angles of secondary exotropia at near and distance fixation were evaluated and the risk factors for secondary exotropia were analyzed.
Results: Four hundred forty-eight patients had retroequatorial myopexy on both medial rectus muscles with recessions. Three hundred forty-nine of 448 patients maintained satisfactory near and distance binocular alignment at the final follow-up. Secondary exotropia occurred in 37 of these patients and residual esotropia occurred in 62 patients. There were no significant differences between the incidences and angles of secondary exotropia at near and distance fixation. The preoperative absence of binocularity was the only independent risk factor for developing secondary exotropia after a retroequatorial myopexy of medial rectus muscle with recession.
Conclusion: We determined that secondary exotropia was not a common result of retroequatorial myopexy of the medial rectus muscles with recession. We determined that the preoperative absence of binocularity was the only independent risk factor identified in this study.