Long-Term Results of Intermittent Exotropia Surgery: Comparison between Motor and Functional Success

ABSTRACT

PURPOSE: To evaluate the long-term surgical success rate (>3 years) and contributing success factors considering motor and sensory criteria for patients with intermittent exotropia. METHODS: Fifty-four patients who received surgery for intermittent exotropia and were followed-up for a minimum of 3 years, including reoperation, were retrospectively evaluated. The first procedure was unilateral recession and resection in 50 patients and bilateral lateral rectus recession in 4 patients. Patients were classified as achieving a good, fair or poor outcome based on motor and sensory criteria. Success rate and associated factors such as postoperative alignment, exotropia type, first surgical procedure, and proportion of patients receiving reoperations were analyzed. RESULTS: The mean follow-up period after the first surgery was 4.81 +/- 1.30 years. The good outcome was achieved in 32 patients (59.3%), fair in 14 patients (25.9%), and poor in 8 patients (14.8%) considering motor criteria only. The good outcome was achieved in 29 patients (51.9%), fair in 12 patients (22.2%), and poor in 14 patients (25.9%) when considering combined motor/sensory (functional) criteria. No patient who received bilateral lateral rectus recession as the first procedure belonged to the good outcome group (p = 0.03 by motor criteria and p = 0.044 by functional criteria). Patients who received reoperation were significantly more likely to be in the good and fair groups (p = 0.009 by motor criteria and p = 0.02 by functional criteria). CONCLUSIONS: Long-term surgical results of intermittent exotropia in this Korean population revealed 85.2% motor success rate and 74.1% functional success rate. Early postoperative overcorrection was not associated with long-term success. Recession and resection procedure and reoperations were significantly associated with better outcome based on motor and functional criteria. Diligent reoperations after the first surgery could possibly contribute to good long-term functional outcome in intermittent exotropia patients.