Unilateral Medial Rectus Recession for Correction of 20 to 30 ∆ of Esotropia

Purpose To evaluate the effect of unilateral medial rectus (MR) recession for the correction of 20 to 30 ∆ of esotropia.Methods Pediatric patients with esotropia (ET) with a surgical target of 20 to 30 prism diopters (∆) were included in a prospective study to determine the effect of unilateral MR recession. The surgical target angle was calculated as the average of the distant angle with glasses and near without glasses, or the average of distant and near angles without glasses (if non-significant refractive error), or the average of near angles with and without glasses (if ET was measured using the modified Krimsky test). The study endpoint was the last follow-up visit, conducted at least 3 months postoperatively. A successful motor outcome was defined as orthotropia or a horizontal tropia of 10∆ or less at distance and near.Results The study included 21 patients, 1 to 12 years of age. Patients were followed up for 3 to 43 (mean+/-SD 12.5+/-10.6) months. A successful outcome was achieved in 85.7%, with no correlation to the surgical target angle or the amount of recession (p > .05). The 14.3% failure rate was attributed to undercorrections. Persistent lateral incomitance was observed in 10.5% of cases and was not correlated with the surgical target angle or the amount of recession (p > .05). Persistent limited ductions were mild (−1).Conclusions This prospective study of pediatric patients showed that unilateral MR recession is a reasonable surgical approach for treating esotropia of 20–30 ∆, with small rates of undercorrection and duction limitation, and no overcorrection.