Comparison of Unilateral Versus Bilateral Lateral Rectus Recession for Small Angle Intermittent Exotropia: Outcomes and Surgical Dose-Responses.

Abstract

To compare the surgical outcomes of unilateral lateral rectus recession to bilateral lateral rectus recession for small angle intermittent exotropia. This was a retrospective cohort study of pediatric patients with an intermittent exotropia between 16 and 20 prism diopters (PD) who underwent unilateral lateral rectus recession or bilateral lateral rectus recession at a single tertiary care pediatric hospital. The primary outcome was success (exotropia < 10 PD of esotropia < 5 PD, no decrease in stereopsis > 0.6 log arcsec, and no reoperation) at 12 months postoperatively. Secondary outcomes included survival analysis of time to surgical failure, surgical dose-response, and improvement in central fusion or stereopsis. At 12 months, successful outcomes were achieved in 13 of 27 patients (46%) in the bilateral lateral rectus recession group and 19 of 28 patients (70%) in the unilateral lateral rectus recession group, which was not a statistically significant difference (P = .10). Survival analysis showed a trend toward a higher rate of failure in the bilateral lateral rectus recession group compared to the unilateral lateral rectus recession group (P = .04). The mean surgical dose-response was 1.7 PD/mm at 1 week and 1.0 PD/mm at 12 months for the bilateral lateral rectus recession group, and 2.0 PD/mm at 1 week postoperatively and 1.4 PD/mm at 12 months postoperatively for the unilateral lateral rectus recession group. There were no cases of long-term postoperative lateral incomitance in either group. Unilateral lateral rectus recession and bilateral lateral rectus recession have similar success rates for small angle intermittent exotropia after at least 12 months of follow-up. Randomized controlled trials in surgical management of intermittent exotropia should consider unilateral lateral rectus recession as a treatment arm. [J Pediatr Ophthalmol Strabismus. 2022;59(5):350-355.].