Comparison of surgical outcomes between bilateral recession and unilateral recession-resection in moderate-angle intermittent exotropia

Abstract

To compare postoperative drift after bilateral lateral rectus recession (BLR) and after unilateral recession combined with medial rectus resection (R&R) in children with primary moderate-angle intermittent exotropia. The medical records of children with intermittent exotropia in the range of 25Δ-50Δ who underwent BLR or R&R from July 2015 to September 2016 were reviewed retrospectively. Outcomes were classified according to postoperative angle of deviation at distance as overcorrection (esophoria or -tropia of >5Δ), success (esophoria or -tropia of ≤5Δ to exophoria/tropia of ≤10Δ), or recurrence (exophoria or -tropia of >10Δ). Patients were examined on postoperative day 1 and at 6weeks, 6months, and 12months. Sensory status was evaluated using the Titmus stereoacuity test. A total of 330 children were included (BLR, 175; R&R, 155). Exotropic drift was greater in the R&R group in the period between day 1 and 6weeks and from 6 to 12months (P <0.05). Surgical successful rates in each group were comparable: 57.7% in the BLR group and 60.6% in the R&R group (P>0.05). However, higher overcorrection rates were noted in the BLR group at 6 and 12months (16.6% vs 6.5 % at 12months [P=0.003]). There were more patients with deteriorated stereopsis after surgery in the BLR group (P=0.025). In our study cohort, BLR was associated with more stable long-term ocular alignment and a higher rate of overcorrection than R&R. Postoperative day 1 overcorrection of <16Δ following R&R and of <10Δ following BLR were associated with relatively good results.