Strabismus Surgery of Consecutive Exotropia

The purpose of this study was to determine the surgical outcome, dose-effect (DE), and degree of binocularity in patients undergoing surgery for consecutive exotropia following initial surgery of esotropia.

Twenty-one patients were identified. We analyzed the mean angle of deviation pre- and postoperatively as measured with the alternate prism cover test, DE, and binocularity.

All patients had had previous strabismus surgery. The surgery for consecutive exotropia had been performed at a mean age of 35.92 ± 18.26 years. In 19 of these patients, surgery of consecutive exotropia involved at least one previously operated extraocular muscle, and the mean interval to the previous surgery was 25.67 ± 16.14 years. The mean angle of deviation (DE) at distance and in the primary position was - 33.43 ± 12.75 prism diopters (PD) preoperatively, + 0.76 ± 7.91 PD 1 week after surgery, and - 7.24 ± 12.14 PD 3 months after surgery. The mean DE was 3.58 ± 1.53 mm/PD at 1 week and 2.70 ± 1.78 mm/PD at 3 months post-surgery. Postoperatively, 62% patients had a binocularity of at least Bagolini positive, 33% had either a positive TNO or Titmus Test, and 24% were Lang I positive (550″).

Performing strabismus surgery with consecutive exotropia results in restoration of some binocularity in a large number of patients, even in adults, and should be considered as a possibility. The dose-effect is comparable to conventional surgery of exotropia.