Bilateral surgery recommended for residual esotropia greater than 15 PD

This retrospective case series describes the effect of graded unilateral versus bilateral lateral rectus resection for the treatment of residual or recurrent esotropia after maximal medial rectus muscle recession. The authors reviewed 38 pediatric cases of two strabismus surgeons at one institution that were evaluated for residual or recurrent esotropia after maximal medial rectus recession for infantile or large-angle nonaccommodative esotropia.

Each patient underwent initial eye muscle surgery for angles of 40 to 60 prism diopters (PD) (medial rectus recession of 5.5 to 6.5 mm, 11.0 to 11.5 mm from surgical limbus). Unilateral lateral rectus resection ranging from 4 to 7 mm resulted in mean esotropic corrections of 10.5 to 14.9 PD. Differences in surgical response per millimeter of unilateral lateral rectus resection were not significant. Bilateral lateral rectus resection of 5, 6 and 7 mm resulted in a mean correction of 19.75, 28.75 and 33.5 PD, respectively.

The authors say their results demonstrate that mean values for esotropic correction increase with larger amounts of lateral rectus resection and can produce highly variable results on a case-by-case basis, although these differences were not significant for unilateral lateral rectus surgery. They conclude that unilateral surgery can be appropriate for residual esotropia of up to 15 PD, while larger residual deviations should be addressed with bilateral surgery.