Periosteal muscle anchoring for large angle incomitant squint

Abstract

Purpose: To describe a surgical technique for correcting very large angle exodeviations and determine long term outcomes leading to the evolution of surgical technique.

Methods: A consecutive series of seven patients with large angle, incomitant squint were operated on at Moorfields Eye Hospital over a five-year period using periosteal anchoring by a joint Strabismus/Adnexal team. All patients underwent anchoring of the insertion of the medial rectus (MR) muscle to the periosteum of the medial orbital wall via a retrocaruncular approach, with or without lateral rectus (LR) disinsertion and suturing to the lateral orbital rim connective tissue. Retrospective analysis of notes assessed previous procedures, prism dioptre (PD) deviations and complications.

Results: Included were seven eyes (five right, two left) of seven patients (two female, five male). Median age at first anchoring procedure was 25 years (range 4-57). Mean follow up was 34 months (range 8-66). Six patients had long-standing third nerve palsy, one patient had Moebius syndrome. Pre-operative exotropia ranged from 45 to 115 PDs (mean 76, median 75). At the final follow up, all patients had reduced horizontal deviations ranging from 0 to 80 PDs (mean 34, median 30). Further surgery was required in three patients all of whom did not undergo release of the LR muscle at the first procedure.

Conclusion: Large angle incomitant divergent squints present a particularly difficult surgical challenge. We advocate a combined bi-rectus fixation approach to hold the globe in the primary position.