Analysis of risk factors for consecutive exotropia and review of the literature.

Purpose: To evaluate the possible risk factors in patients with consecutive exotropia following esotropia surgery.

Methods: Medical records of patients who had comitant esotropia surgery between June 1999 and April 2011 were reviewed. Those who developed consecutive exotropia composed the exotropia group; patients matched for age and duration of follow-up who did not develop consecutive exotropia composed the no exotropia group. The charts of the patients were reviewed and possible risk factors for development of consecutive exotropia were investigated.

Results: The average ages of 47 patients in the exotropia group and 54 patients in the no exotropia group were 10.8 ± 8.7 years (range: 1 to 41 years) and 8.5 ± 6.3 years (range: 1 to 30 years), respectively (P = .292). Amblyopia was detected in 31 (66%) and 12 (22.2%) patients in the exotropia and no exotropia groups, respectively (P = .004). Anisometropia was observed in 20 patients (42.6%) in the exotropia group and 5 patients (9.3%) in the no exotropia group (P = .003). Preoperative average esodeviation values were 42.5 ± 8.3 prism diopters (PD) (range: 25 to 60 PD) in the exotropia group and 42 ± 9.4 PD (range: 20 to 65 PD) in the no exotropia group (P = .673). Postoperative deviations were 32.8 ± 23 PD exotropia (range: 10 to 90 PD exotropia) in the exotropia group and 4.4 ± 4.2 PD esotropia (range: 0 to 10 PD esotropia) in the no exotropia group (P = .000). Asymmetric surgery had been performed in 61.7% of the exotropia group (n = 29) and 9.3% of the no exotropia group (n = 5) (P = .000). Limitation of adduction was detected in 14 patients (29.8%) in the exotropia group; none was noted in the no exotropia group (P = .000). The mean interval between the initial surgery and the onset of consecutive exotropia was 11.1 ± 15.1 months (range: 0 to 126 months).

Conclusions: Anisometropia, amblyopia, asymmetric surgery, and postoperative adduction deficit were associated with the development of consecutive exotropia. Long-term follow-up should be considered because consecutive exotropia can develop after months or years.