Large-angle strabismus: can a single surgical procedure achieve a successful outcome?

Large-angle strabismus is a gray zone for surgeons with various advocates for one, two-, three-, or even four-muscle surgeries. Very frequently, reoperations are required in these cases in order to achieve a successful outcome. In this article, the authors evaluate the outcome of concomitant large-angle strabismus after a single surgical procedure.

A retrospective analysis of all operated cases of concomitant large-angle strabismus (50 prism diopters or more) during a 1.5-year period was performed from patient's case files. A successful outcome of surgery was defined as deviation within 10 prism diopters of orthophoria/tropia for both distance and near.

Fifty patients met the inclusion criteria. The overall success rate was 60%, with the esotropia group having a higher success rate (68.75%) than the exotropia group (44.45%). Ten patients underwent recess-resect procedure, 20 had bimedial rectus recession, and 3 had bilateral lateral rectus recession, while 17 patients had surgery on 3 horizontal rectus muscles. Thirty-three patients had two-muscle surgery with a success rate of 57.58%, while 17 patients had three-muscle surgery with a success rate of 64.71%, the difference being statistically insignificant. There was no statistically significant difference between the various age groups analyzed for overall success rate, suggesting that age group is not a factor for positive outcome in large-angle strabismus surgery. A total of 12 patients were amblyopic at the time of strabismus surgery and they had a success rate of 33.33%, which was much poorer than the success rate (68.42%) of the remaining 38 patients who did not have amblyopia at the time of surgery.

A good surgical outcome can be obtained in large-angle strabismus with a single surgical procedure, though a randomized controlled study needs to be done to establish whether three-muscle surgeries give better results than two-muscle surgeries.