Comparison of Medial Rectus Recession Versus Lateral Rectus Resection in Divergence Insufficiency Esotropia: A Comparative Analysis

Purpose: We compared the surgical outcomes of medial rectus recession (MR Rc) and lateral rectus resection (LR Rs) in patients with divergence insufficiency esotropia, characterized by greater esotropia (ET) at distance than at near.Methods: This retrospective comparative study included 22 patients who underwent either MR Rc or LR Rs for divergence insufficiency esotropia, defined as comitant ET with >8 prism diopters (PD) difference between distance and near, with persistent diplopia at distance. Surgical success was defined as final deviation <8 PD with diplopia-free status at distance and near at 12 months postoperatively. The mean dose-response ratio (PD/mm) of each surgical technique was analyzed.Results: Of the 22 patients, 13 underwent MR Rc and 9 underwent LR Rs. The surgical success rate was higher in the LR Rs group than in the MR Rc group; however, the difference was not statistically significant (69% vs. 100%, p = 0.11). In the MR Rc group, three patients had under-correction and one had over-correction. The mean dose-response ratio for distance was 2.43 ± 0.51 PD/mm at 1 week and 2.15 ± 0.93 PD/mm at 12 months, whereas for near it was 1.89 ± 0.83 and 1.69 ± 1.06 PD/mm, respectively. In the LR Rs group, all patients achieved surgical success. The mean dose-response ratio for distance was 1.96 ± 0.46 and 1.91 ± 0.51 PD/mm at 1 week and 12 months, whereas for near it was 1.23 ± 0.42 and 1.13 ± 0.52 PD/mm, respectively.Conclusions: Both surgical techniques demonstrated favorable outcomes for divergence insufficiency esotropia. However, the dose-response ratio was more predictable in LR Rs surgery. For MR Rc, augmented surgical approaches may be considered to improve predictability and success rates.