Fenestration of Medial Rectus Muscle versus Combined Resection Recession for Management of Near-Distance Disparity Esotropia

Purpose: To compare the effectiveness of two distinct surgical methods for treating near-distance disparity (NDD) esotropia: fenestration and combined resection-recession of medial rectus (MR) muscle. Methods: This retrospective study involved 44 patients with convergence excess esotropia who had been using their full cycloplegic refraction and/or bifocal glasses for at least 6 months and still had NDD esotropia. We compared results of two surgical techniques: Group I underwent fenestration of both medial recti muscles, which involved excising a central rectangle from the muscle insertion to a point 5– 8 mm back, depending on the angle of the esotropia, while preserving the superior and inferior longitudinal muscle sleeves. Group II received a combined resection of both medial recti, 2.5 mm from the insertion, then recession based on near-angle esotropia, adding 1 mm of recession for each muscle. Satisfactory outcome was defined as deviation of ≤ 8 prism diopters within orthophoria and a reduction of NND to ≤ 8 prism diopters at 6-month follow-up. Results: There was statistically significant difference between both groups at 6-month follow-up. In Group I, 71.4% of patients achieved a NDD of ≤ 8 prism diopters, with 6 cases showed undercorrection. In Group II, 96% of cases achieved satisfactory results, with no undercorrection; one case had overcorrection resulting in consecutive exotropia. Conclusion: Fenestration technique showed inferior results to combined resection–recession. However, it offers good alternative to combined resection-recession as it is simple, suture-less and quick operation. Though, surgical doses may need to be revised in future studies. Keywords: near-distance disparity, fenestration, esotropia, accomodative convergence/accomodation ratio, NDD, AC/C ratio