Surgical Outcomes of Transposition Surgery for the Correction of Large-Angle Strabismus.

Background: Many potential surgical options exist to address large-angle deviations and head turns that result from various forms of paralytic strabismus. Muscle transposition surgeries serve as suitable alternatives to simple resection-recessions. Here, we report outcomes of augmented Hummelsheim and X-type transpositions for the correction of large-angle strabismus and provide insights for surgical planning.

Methods: We performed a retrospective chart review of 40 consecutive patients with strabismus who were treated with an augmented Hummelsheim or X-type transposition surgery at a single academic medical center. Etiologies included cranial nerve palsies (n = 26), monocular elevation palsy (n = 3), Duane syndrome (n = 1), traumatic extraocular muscle damage (n = 8), and chronic progressive external ophthalmoplegia (n = 2). All patients were followed for a minimum of 2 months postsurgery. Logistic regression analyses were performed to assess for predictors of surgical outcome.

Results: Forty consecutive patients were enrolled in our series. The median preoperative deviation was 46.5Δ (interquartile range [IQR] 35-70). The median postoperative deviation 2 months after surgery was 0.5Δ (IQR 0-9.5), which represented a significant improvement (P < 0.001). Thirty-three patients (82.5%) experienced an improvement in range and/or centration of binocular single vision (BSV). More patients who underwent an augmented Hummelsheim procedure and had a small overcorrection at postoperative day 3 had a favorable result on postoperative month 2 (79%) compared with those that were initially under-corrected (38%). Multiple logistic regressions found larger preoperative deviation (P < 0.005) and esotropia (P < 0.021) to be predictors of a less favorable surgical outcome (C-statistic = 0.83). Subgroup analysis revealed that less, favorable outcome after X-type transposition occurred most frequently in patients undergoing correction of an esodeviation.

Conclusion: Augmented Hummelsheim transposition techniques offer effective treatment options for paralytic strabismus with esotropic deviations, whereas X-type transpositions are effective for exotropic deviations and deviations from severe inferior rectus damage. In addition to potentially providing a wider field of BSV, improved centration is often achieved.