Background/Aims To compare the long-term surgical outcomes between unilateral lateral rectus recession-medial rectus resection (RR) and lateral rectus recession-medial rectus plication (RP) in children with intermittent exotropia.

Methods Children who underwent RR or RP for intermittent exotropia between January 2008 and July 2016, with a minimum follow-up period of 2 years were retrospectively reviewed. Postoperative angle of deviations and clinical factors including sex, age, refractive errors, preoperative angle of deviation, types of exotropia and stereopsis were investigated. Based on the angle of deviation at year 2, surgical outcomes were classified into two groups as follows: success (esodeviation ≤5 prism dioptres (PD) to exodeviation ≤10 PD) and failure (overcorrection (esodeviation >5 PD) and undercorrection or recurrence (exodeviation >10 PD)).

Results Of the 186 patients, 114 underwent RR and 72 underwent RP. The angle of exodeviation steadily increased over time in both groups after surgery. The durations of exodrift were longer in the RP group than in the RR group. The surgical success at postoperative year 2 was 55.3% in the RR group and 27.8% in the RP group (p<0.001). The amount of overcorrection was associated with successful outcomes in both groups.

Conclusions In children with intermittent exotropia, RR group presented better surgical outcomes than RP group. The amount of initial overcorrection was important to achieve favourable outcomes in children with intermittent exotropia.