Long-term results of the surgical management of intermittent exotropia

To examine long-term surgical success rates (>10 years) for patients with intermittent exotropia and the risk factors for failure of surgery in these patients.

An attempt was made to contact all patients who underwent surgical treatment for intermittent exotropia between the years of 1970 to 1998 with a minimum postoperative follow-up of 10 years. Each patient underwent a detailed sensory and motor examination, including measurements of near and distance stereoacuity, cover testing, and ocular rotations. Patients were classified as achieving an excellent, fair, or poor outcome on the basis of motor and sensory outcomes. Risk factor analysis was performed to evaluate associations with a poor outcome and reoperations.

Of 197 patients identified, 50 were reevaluated. When combined motor/sensory criteria for surgical success were used, we found that 38% of patients achieved an excellent outcome, whereas 34% and 28% achieved a fair or poor outcome, respectively. When only the motor criteria were used, we found that 64% had an excellent outcome, whereas the remaining patients achieved either a fair (18%) or a poor (18%) outcome. During the follow-up period, 60% of patients required at least one reoperation. Multivariate risk factor analysis determined that anisometropia (p = 0.03) was associated with a poor outcome, whereas postoperative undercorrection (p = 0.04) and lateral incomitance (p = 0.06) were associated with reoperations.

Long-term surgical results in intermittent exotropia are less encouraging when sensory status is added to the evaluation. Patients with anisometropia, lateral incomitance, and immediate postoperative undercorrection are at increased risk for poor outcomes and to require reoperations.