The risk factors increasing the recurrence of intermittent exotropia following surgery

Purpose: To evaluate the factors and preoperative clinical features associated with recurrence after surgical correction of intermittent exotropia (IXT). Methods: The medical files of patients who underwent surgery for IXT at a single center between July 2021 and June 2024 were retrospectively reviewed. Final motor success was defined as ocular alignment within 10 prism diopters (PD) of exodeviation to 5 PD of esodeviation at both distance and near. Recurrence was defined as a postoperative deviation greater than 10 PD at distance and near during follow-up. Factors evaluated included age at surgery, duration between symptom onset and surgery, preoperative angle of deviation, stereoacuity, binocular fusion, spherical equivalent, type of surgery, presence of amblyopia, fixation preference and other associated strabismic features. The relationship between these factors with and recurrence was analyzed. Result: A total of 58 patients (34 male, 58.5%) were included. The mean age was 21.2 ± 11.7years, and the mean follow-up was 12.3 ± 5.3months. Forty-one patients underwent bilateral lateral rectus recession, three underwent unilateral lateral rectus recession with medial rectus resection, and 14 underwent combined operation, bilateral lateral rectus recession with oblique muscle - weakening procedures. Surgical success at final visit was achieved in 34 (58.6%). There was no relation between recurrence and the type of intermittent exotropia in patients, sex, age at surgery, family history, consanguinity, amblyopia, anisometropia, abnormal ocular motility, fixation preference, binocular function, or surgical method (p >.05). However, a long duration of exotropia and high preoperative deviations at both distance and near were found to be related to postoperative recurrence. Conclusions: The overall surgical success rate in this study was 58.6%. Moreover, longer duration of preoperative exodeviation and larger preoperative deviation at both distance and near were identified as significant risk factors for postoperative recurrence.