Exotropic drift and ocular alignment after surgical correction for intermittent exotropia

Abstract

Purpose: To evaluate changes in the angle of deviation over time and compare the motor success rate with different initial postoperative deviation in patients undergoing surgical correction for intermittent exotropia.

Methods: Forty-eight patients aged between 1 and 10 years who underwent bilateral lateral rectus recession for intermittent exotropia were retrospectively evaluated. Preoperative and postoperative ocular deviations at 1 week, 1 month, and 6 months were analyzed. Full surgical correction was attempted in all patients. Motor success was defined as ocular deviation within 10 prism diopters of orthophoria at 6 months postoperatively.

Results: The follow-up period ranged from 6 months to 3 years. Although most patients had exotropic drift, this drift was greater in patients with initial esotropia (86.7%) and orthophoria (70.0%) compared to patients with exotropia (26.1%). Motor success was achieved in 29 (60.4%) patients. There was no statistical difference between ocular alignment at 1 week postoperatively and final motor success (P = .782). There was good correlation between ocular alignment at 1 week and 6 months postoperatively (rho = 0.585, P < .001). Age and preoperative deviation were not found to be associated with motor success.

Conclusions: The success rate appears to be unaffected by initial ocular alignment, suggesting that deliberate initial overcorrection may be unnecessary. Future studies are warranted to evaluate the long-term stability of this alignment.