Medial Rectus Inferior Plication in the Management of Near Exodeviations

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.

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.

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.

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.