Long-term evaluation of two reoperation groups for intermittent exotropia

To evaluate the effect of initial postoperative deviation on subsequent reoperation in patients with intermittent exotropia and to compare the clinical factors and surgical outcomes between the two surgical failure groups.

The medical records of patients who underwent reoperation after failed primary surgery for intermittent exotropia at a single center were reviewed retrospectively. Patients with recurrent intermittent exotropia and consecutive esotropia were considered surgical failures. Various clinical factors were compared between these two groups, including age at surgery, interval between surgeries, stereoacuity, spherical equivalent, office control, surgical type, presence of neurologic disease, amblyopia and other strabismus, and postoperative angles of deviation.

Of the 3,406 patients who underwent surgery for intermittent exotropia, 139 patients met inclusion criteria. Of these, 125 (3.8%) underwent reoperation for recurrent intermittent exotropia; 14 (0.4%), for consecutive esotropia. On postoperative day 1 the intermittent exotropia group showed esodeviation at distance fixation of 2^Δ ± 4^Δ; the esotropia group, esodeviation of 5^Δ ± 4^Δ. The intermittent exotropia group showed a significant progression of exodeviation from 2 months postoperatively (all P < 0.005). In the esotropia group, the amount of esodeviation significantly improved in postoperative months 2 and 6 (P = 0.024 and 0.013) then further worsened after 6 months. The interval between the first and second surgeries was 64 ± 28 months in the exotropia group and 55 ± 36 months in the esotropia group, a significant difference (P = 0.003).

Initial postoperative overcorrection following primary surgery for intermittent exotropia may not predict long-term success. Careful monitoring for consecutive esotropia is needed 6 months postoperatively, and annual check-ups are recommended for all patients with under- and overcorrections for a period of at least 5 years after surgery.