Recurrence of intermittent exotropia: factors associated with surgical outcomes

The surgery of choice for intermittent exotropia (XT) continues to be debated, with little evidence that one procedure provides a more successful outcome than the other in the longer term. Many factors, however, may potentially influence the outcome of strabismus surgery for intermittent XT. This study aimed to investigate factors associated with the recurrence of an exo-deviation following horizontal muscle surgery for intermittent XT of the divergence excess type.

We retrospectively reviewed the medical histories of patients who underwent surgery for the correction of intermittent XT between January 1998 and June 2005. The factors analyzed were as follows: sex, age of onset, age at initial surgery, family history, size of preoperative deviation, near binocular single vision, amblyopia, oblique dysfunction, refractive error, type of surgery, and postoperative alignment.

Eighty-nine patients were included in the final analysis. Of these, 19 demonstrated recurrence of their deviation. The mean follow-up period was 2 years. None of the factors analysed appeared to influence the outcome of intermittent XT surgery.

We found that no single factor influenced patients' responses to the surgical treatment of intermittent XT. To address controversies and improve the evidence base regarding surgical intervention of this condition, randomized controlled trials are needed and justified because the results indicate that it would be relatively safe to randomly allocate patients to groups who could receive differing treatments so as to determine optimum management strategies.