Bilateral, unilateral two-muscle surgery show similar outcomes in large-angle exotropia

This retrospective study found similar long-term success rates between bilateral and unilateral two-muscle rectus recession in children with primary large-angle exotropia.

The authors evaluated the long-term outcomes of single-staged two-muscle surgery in 86 children with primary large-angle exotropia of ≥40 prism diopters (PD) who were followed for more than two years.

After a median follow-up of three years, the successful alignment rate was 64%. Overall surgical outcomes were comparable between patients who underwent bilateral and unilateral procedures.

However, in patients with exotropia of ≥45 PD, the unilateral procedure resulted in more favorable long-term outcomes. The overcorrection rate was higher in the unilateral group up to two years, but no significant difference was found after two years. The only significant risk factor for recurrence was the magnitude of preoperative exodeviation.

To the best of the authors’ knowledge, this is the first long-term study comparing the surgical outcomes of bilateral and unilateral rectus recession procedures in children with primary large-angle exotropia. They note that for bilateral procedure patients, the mean time to recurrence was shorter but the mean time from recurrence to reoperation was longer. This may have been due to the relatively small magnitude of immediate postoperative exodrift in these patients, which led them to prefer trying nonsurgical treatments for quite a while before reoperation.