Early postoperative changes of motor alignment after surgery for intermittent exotropia

Purpose: To evaluate the early postoperative changes of the angle of deviation after surgery for intermittent exotropia. Methods: We retrospectively reviewed the medical records of 114 patients who had been surgically treated for intermittent exotropia and followed-up on postoperatively for 1 month or more. Patients were observed at postoperative 6 h, 1 day, 1 week, and 1 month. The main outcome measure was the change of the angle of deviation during the early postoperative period (from 6 h to 1 day postoperatively). Results: The mean preoperative angle of exodeviation was 26.3 ± 7.6 PD at distance and 25.4 ± 10.3 PD at near. The angle of deviation was −3.3 (esodeviation) ± 7.0 PD at distance and −0.7 ± 7.1 PD at near at postoperative 6 h, and −3.7 ± 6.9 PD and −0.8 ± 6.8 PD at postoperative 1 day. Neither of these sets represented a significant change from 6 h to 1 day postoperatively (p = 0.300 at distance, p = 0.945 at near). However, in 25 patients (21.9%) the angle of deviation changed 5 PD or more from 6 h to 1 day. Among them, ten showed exodrift and 15 esodrift. At postoperative 1 month, the deviations became significantly more exotropic compared with postoperative 1 day (p < 0.001). Conclusions: The mean angle of deviation showed no significant change from 6 h to 1 day postoperatively, but 21.9% of patients showed a change of 5 PD or more in this period. These results should be considered in determining the time and the target angle of adjustment in adjustable strabismus surgery for exotropia.