Three-muscle surgery for very large-angle constant exotropia.

PURPOSE

To report the outcomes of surgery on three horizontal muscles for very large-angle constant exotropia.

METHODS

In this prospective case series, consecutive adult patients with primary constant exotropia with angles ≥120(Δ) underwent strabismus surgery on three horizontal muscles. Surgery consisted of lateral rectus recession of 10-15 mm on the fixing eye in addition to lateral rectus recession of 9-13 mm and medial rectus resection of 6.5-9 mm on the nonfixing eye. The mean follow-up period was >6 months. Success was defined as horizontal eso- or exodeviations of ≤10(Δ).

RESULTS

A total of 23 patients were included. The mean age at surgery was 30.4 ± 9.3 years (range, 16-52). The mean preoperative near exodeviation was 128(Δ) ± 9.8(Δ); the mean preoperative distance exodeviation, 130(Δ) ± 10.4(Δ). The mean follow-up period was 8.1 ± 1.4 months. At the last follow-up, 19 of the 23 cases (83%) were successfully aligned. At final follow-up examination, the mean postoperative exodeviation was 5(Δ) ± 4.2(Δ) (near) and 5(Δ) ± 4.3(Δ) (distance); no patient had diplopia on lateral gazes.

CONCLUSIONS

In this patient cohort, surgery on three-muscle surgery for very large-angle exotropia successfully restored alignment in primary gaze in over 80% of cases without inducing symptomatic abduction deficits.