Long-term Results of Slanted Recession of Bilateral Lateral Rectus Muscle for Intermittent Exotropia with Convergence Insufficiency

Abstract

Purpose: To evaluate the long-term efficacy of slanted lateral rectus recession in children for reducing distance and near exodeviation and near-distance deviation difference in intermittent exotropia with convergence insufficiency.

Methods: The medical records of 53 patients with convergence insufficiency intermittent exotropia who underwent slanted bilateral lateral rectus recession performed by a single surgeon and received follow-up for more than 12 months were retrospectively analyzed. Deviation angles at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively and on the last visit were reviewed. Surgical success was defined as postoperative residual distance and near deviation angles ≤8 prism diopters and a difference between the near and distance angles ≤8 prism diopters.

Results: The mean duration of follow-up was 24 months (range, 12 to 61 months). On the last visit, the residual deviation angles were ≤8 prism diopters in 75.5% for distance, 62.3% for near, and 81.1% for the near-distance difference. Surgical success was achieved in 31 (58.5%) patients, and none of them manifested limitations in eye movements or diplopia at the last follow-up visit.

Conclusions: Slanted lateral rectus recession is an effective surgical method for reducing distance and near exodeviation and near-distance deviation difference in intermittent exotropia with convergence insufficiency.

Keywords: Intermittent exotropia; Near-distance difference; Ocular motility disorders; Slanted lateral rectus recession.

Fig. 1. Distance deviation, near deviation, and near-distance difference over time. The mean distance deviation angle decreased from 23.2 prism diopters (PD) preoperatively to 2.6 PD postoperatively, the mean near deviation angle decreased from 33.8 PD preoperatively to 6.2 PD postoperatively, and the mean difference between the near and distance angles decreased from 10.6 PD preoperatively to 4.0 PD postoperatively.