Factors influencing the outcome of strabismus surgery in patients with exotropia.

PURPOSE: To determine the factors associated with favorable and less favorable outcomes in strabismus surgery for treatment of exotropia and to show the factors influencing the efficacy of the surgical procedure.

METHODS

Case files of 225 patients with a diagnosis of primary exotropia were evaluated. Information about patient age at onset of deviation, patient age at surgery, interval between onset and surgery, preoperative deviation, refractive errors, degree of anisometropia, visual acuity, presence of amblyopia, presence of an A- or a V-pattern, amount of surgery performed, type of exotropia (intermittent or constant), and existence of binocular single vision before surgery were obtained and evaluated using multiple regression analysis.

RESULTS

Preoperative deviation and refractive errors were proved to be significant factors influencing a favorable outcome in patients with surgically treated exotropia (r(2) = 0.12, P <.001, and r(2) = 0.07, P <.001 respectively). Preoperative deviation, amount of surgery performed, and refractive errors shifting toward myopia significantly influenced the efficacy of the surgery performed (r(2) = 0.31, 0.06, and 0.025, respectively).

CONCLUSION

Special care should be paid to refractive errors in patients with exotropia before determining the amount of surgical intervention.