To evaluate long-term outcomes of surgery for intermittent exotropia.

The authors evaluated 78 patients who underwent surgery for intermittent exotropia and were available for a follow-up over a 5-year period. According to distant exodeviation and fusion control at the last visit, the patients were classified into either the stable group (distant exodeviation ≤10 PD) or the recurrent group (distant exodeviation >10 PD). The recurrent group was reclassified into the clinical success group (distant exodeviation >10 PD, <20 PD with good fusion control) or the clinical failure group (distant exodeviation ≥20 PD or distant exodeviation >10 PD, <20 PD with poor fusion control). We analyzed recurrence rate, success rate, and clinical outcome.

Recurrence rate was 65.3% (n = 51), and the surgical success rate calculated as the rate of stable group and clinical success group was 73% (n = 57). The postoperative angle of exodeviation was more decreased than the preoperative angle in 93.6% of patients. When comparing postoperative with preoperative sensory function, only 2.6% of patients demonstrated worse distant fusion control grades, 66.7% of patients remained the same, 30.8% improved, and 5.1% of patients demonstrated poorer near stereopsis. The rest of patients had better or equal fusion control and stereoacuity. Age at surgery in the recurrent group was less than in the stable group ( p = 0.004) and the recurrent group had worse preoperative distant fusion control ( p = 0.021). Exodeviation angle of the recurrent group at postoperative 1 month, 3 months and 6 months was greater than that of the stable group ( p < 0.005).

Despite a high recurrence rate, surgery for intermittent exotropia showed a high clinical success rate and good long-term efficacy and safety in both deviation angle and sensory function.