Concurrent Medial-lateral Rectus Recessions to Prevent Consecutive Esotropia in Intermittent Exotropia: Explorative Case Series

Purpose: Consecutive esotropia (CET) following intermittent exotropia [IX(T)] surgery can cause significant concern among patients and their parents due to esodeviation and diplopia. We evaluated whether CET can be prevented and explored exotropia recurrence after combined bilateral lateral rectus (LR) and unilateral medial rectus (MR) muscle recession.Methods: This retrospective, exploratory case series included patients who underwent bilateral LR recession for IX(T) of ≥ 25 prism diopters (∆). Thirteen patients demonstrated strong MR tension confirmed by forced duction, and spring-back balance tests during surgery and nasal deviation on the Hirschberg test after LR recession. These patients underwent concurrent bilateral LR and unilateral MR recessions (three-muscle recession). The MR recession ranged from 3 to 5 mm based on the degree of MR tension and nasal deviation. Patients were followed for a minimum of one year (12-73 months) to assess the occurrence of CET (< -5∆) and recurrent IX(T) (> +10∆).Results: The mean age at surgery was 7.60 ± 2.14 years. The mean preoperative IX(T) was 28.62 ± 2.22∆ at far distance and 26.92 ± 10.32∆ at near distance. Postoperative mean deviations were +2.15∆ at 1 month, +2.50∆ at 6 months, +3.83∆ at 1 year, +5.82∆ at 2 years, and +5.33∆ at 3 years. CET (-8∆) developed in two patients, whereas five experienced recurrent IX(T). The mean time to IX(T) recurrence was 18.20 ± 19.23 months post-surgery.Conclusions: In patients with IX(T) ≥ 25∆ and strong MR tension who are at risk of CET, three-muscle recession may offer a novel preventive approach. However, considering the study’s limitations, including its retrospective design, these findings should be interpreted with caution. Future prospective, large-scale randomized controlled trials are needed.