The role of lateral rectus muscle resection for severe esotropia after medial rectus muscle myectomy in Graves' ophthalmopathy.

Purpose: Persistent diplopia after rectus muscle myectomy is not uncommon but challenging in patients with Graves' ophthalmopathy. We investigated the role of lateral rectus muscle resection for patients after medial rectus muscle myectomy in Graves' ophthalmopathy.

Methods: We retrospectively reviewed and collected data from patients with persistent diplopia after medial rectus muscle myectomy for Graves' ophthalmopathy who underwent unilateral or bilateral lateral rectus muscle resection. The eyeball deviations in the primary and reading positions before and after the operation were measured. A successful surgical outcome was defined as having less than five prism diopters (PD) in the primary gaze and functional binocular vision in the central 30° field postoperatively.

Results: A total of fifteen patients were included (mean post-myectomy deviation: 35.9 PD, range: 14 to -75 PD). The lateral rectus muscle resection after medial rectus muscle myectomy achieved an 80.0% success rate, with one patient over-corrected and two patients under-corrected.

Conclusions: The lateral rectus muscle resection is an effective and predictable procedure for managing residual esotropia in Graves' ophthalmopathy patients who have previously undergone medial rectus muscle myectomy.