Augmented bilateral lateral rectus recessions in basic intermittent exotropia.

PURPOSE: To compare the outcomes of conventional surgery with the outcomes of surgeries using augmented amounts of symmetric lateral rectus recessions in the treatment of patients with basic intermittent exotropia. METHODS: One hundred seven patients were enrolled in this study; the patients were followed for more than 6 months. The study group was composed of 41 patients who had undergone conventional surgery, and 66 who had augmented surgery. The amount of recession in conventional surgery was determined according to Parks' formula; the augmented amount ranged from 1.5 to 2.5 mm more per eye in augmented surgery. RESULTS: The success rate was 68.2% in subjects who had undergone augmented surgery, compared with the 43.9% observed in those who had undergone the conventional procedure (p = 0.01). The under correction rate was 53.7% in those who had undergone conventional surgery and 30.3% in those who had undergone augmented surgery (p = 0.02). The overcorrection rate was similar in the two groups (conventional, 2.4%; augmented, 1.5%). CONCLUSIONS: The augmented formula may be preferable to the standard formula for patients undergoing symmetric surgery to correct basic intermittent exotropia.