To compare the surgical outcomes of bilateral lateral rectus recession and unilateral recess-resect (RR) procedure on the nondominant eye for the patients of exotropia with a dominant fixating eye.

Prospective randomized comparative clinical trial.

One hundred twenty-four patients of exotropia with an invariably fixating eye were enrolled to this study. Patients were assigned randomly to two groups, those who underwent bilateral lateral rectus (BLR) recessions (BLR group) or unilateral RR procedures on the nondominant eye (RR group); surgical outcomes were compared. An outcome was considered satisfactory if there was between 10 prism diopters of exophoria/tropia and 10 prism diopters of esophoria/tropia at 6 months after surgery.

In the BLR group, 28 of the 58 patients (48.3%) had a satisfactory outcome, and 30 patients (51.7%) had recurrence. There was no case of overcorrection in the BLR group. In the RR group, 55 of the 66 patients (83.3%) had a satisfactory outcome; 6 patients (9.1%) had recurrence, and 5 patients (7.6%) were overcorrected (P < .001, Fisher’s exact test). All overcorrected patients in the RR group had poor stereoacuity and constant exotropia before the operation. The cumulative probability of surgical success was significantly higher in the RR group than in the BLR group (P = .012, log rank test).

In the patients with exotropia with a dominant eye, the unilateral RR procedure resulted in a better outcome than BLR recession surgery. But, the overcorrection rate was significantly higher in the unilateral RR procedure group, especially in those patients with a poor preoperative stereopsis status and constant exotropia.