Medial Rectus Inferior Plication in the Management of Near Exodeviations

Purpose: To assess outcomes of medial rectus inferior half plication (MR-iP) surgery for the management of near exodeviations, and to define optimal patient selection and surgical dosing for this procedure. Methods: A retrospective analysis of 39 consecutive MR-iP procedures for near exodeviation, performed by a single surgeon, was conducted. Preoperative and postoperative orthoptic measurements, outcomes, and dose–response relationships were evaluated. Results: Thirty-seven patients underwent 39 MR-iP procedures. The mean age was 47 years (range: 12 to 80 years). Of 39 procedures, 56% were unilateral and 44% were bilateral. Preoperatively, mean distance deviation was 5.7 prism diopters (PD), near deviation was 17.7 PD, and near–distance disparity was 12 PD. Postoperatively, mean distance deviation was 4.5 PD, near deviation was 9.8 PD, and disparity was 5.3 PD, representing a 34% reduction in near angle and 56% reduction in disparity ( P < .001). Distance alignment remained unchanged ( P = .08). Overall, 70% achieved surgical success, rising to 90.5% when preoperative near deviation was 20 PD or less, but falling to 44.4% when greater than 20 PD. Complications were rare; one patient developed a self-limiting hematoma due to dysplastic cytopenia. No sustained overcorrections occurred. Mean surgical effect was approximately 2 PD/mm plicated. Conclusions: MR-iP is a well-tolerated, targeted approach for symptomatic near exodeviations, achieving statistically significant reductions in near angle and disparity while maintaining distance alignment. A practical titration dose of 2 PD/mm is recommended. This procedure expands the surgical options for convergence insufficiency exotropia, with low rates of overcorrection.