Early postoperative changes of motor alignment after surgery for intermittent exotropia

To evaluate the early postoperative changes of the angle of deviation after surgery for intermittent exotropia.

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).

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).

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.