Long-term postoperative outcomes of bilateral lateral rectus recession vs unilateral recession-resection for intermittent exotropia.

AIM To discuss the long-term postoperative results of bilateral lateral rectus recession (BLR) and unilateral lateral rectus recession-medial rectus resection (RR) in therapy of intermittent exotropia. METHODS We retrospectively analyzed 213 cases of intermittent exotropia who underwent surgery between 2008 and 2010. The patients were grouped into BLR group and RR group. Motor outcomes were divided into three groups on the basis of the angle of deviation after surgery: overcorrection (esotropia/phoria >5(Δ)), orthophoria (esotropia/phoria ≤5(Δ) to exotropia/phoria ≤10(Δ)), and undercorrection/recurrence (exotropia/phoria >10(Δ)). Titmus test was used to evaluate stereoacuity, the stereoacuity <800s of arc meaned the patients had stereopsis. Surgical outcome including motor criteria and sensory status were compared at postoperative 6, 12, 24mo and at 36mo examination between groups. RESULTS At 12, 24mo after surgery, the motor outcomes had no difference (P>0.05) between groups. However, the motor outcomes at 6, 36mo were signally different in each group, indicating the success rate in RR group at 6mo was higher than that in BLR group (83.02% vs 82.24%, P<0.05) but the result was contrary at the 3y examination (60.75% vs 43.40%, P<0.05). No statistical significance were found in the sensory outcomes between the groups at mean of 3.7y follow-up. CONCLUSION The motor outcomes in RR group were better than in BLR group at 6mo after surgery, while the 3y outcomes were better in BLR group. This may be due to the recurrence rate of the BLR was lower than the RR group's.