Aims To compare surgical outcome of bilateral lateral rectus recession (BLR-rec) and unilateral lateral rectus recession combined with medial rectus resection (R&R) for the basic type of intermittent exotropia (IXT) in children.

Methods Eighty-five consecutive patients aged 3–15 years old with the basic type IXT who underwent surgery and had a minimum postoperative follow-up of 6 months were retrospectively reviewed. Thirty-eight patients underwent BLR-rec and 47 underwent R&R. Successful surgical alignment was defined as esophoria/tropia ≤5 PD (prism dioptres) to exophoria/tropia ≤8 PD in primary gaze while viewing distant or near targets.

Results After a mean follow-up of 14.8±9.5 months, the subjects who had undergone R&R surgery had a significantly higher success rate than those who had BLR-rec surgery (85.1% vs 65.8%, p=0.037). The undercorrection rate was significantly lower in the R&R group than in the BLR-rec group (6.4% vs 23.7%, p=0.023) and there was no significant difference in the overcorrection rate between the two groups (10.5% vs 8.5%, p=1.000).

Conclusions R&R is more effective than BLR-rec surgery in the long term for the basic type IXT in children.