Title : Bilateral medial rectus resection for recurrent exotropia
Abstract:
Purpose: Bilateral lateral rectus (BLR) muscle recession is a common treatment for exotropia; however, under-correction and recurrence remain significant challenges. This retrospective study aimed to evaluate the outcomes of bilateral medial rectus (BMR) resection in patients with residual exotropia (resi XT) after BLR recession.
Method: A total of 39 patients with residual XT≥20 prism diopter (PD) after BLR recession who underwent BMR resection were included. Our primary goal was to assess successful alignment which defined as residual deviation of 10 PD from orthophoria and second and third goal was to determine dose-effect ratio and improvement of stereopsis, respectively.
Result: The mean age at the first surgery was 6.97 ± 2.9 years, and the mean age at reoperation was 12.21 ± 4.34 years. Postoperatively, 76.9% of patients achieved successful alignment. Significant early and late improvements in deviation were noted, with large effect sizes (Hedges's g = 2.91 to 3.33). Stereopsis improved in 41% of cases, and the majority experienced no abduction limitations at the final follow-up. Quantile regression showed a significant association between the amount of MR resection and second surgery effectiveness, with greater resection correlating with better outcomes, especially at the 25th percentile (11.00 PD, p = 0.00054).
Conclusion: Our findings confirmed that bilateral MR resection is an effective surgical option for residual exotropia, with significant improvements in alignment and stereopsis. Further studies with larger samples and standardized protocols are needed to refine surgical strategies for recurrent exotropia.
