Medial rectus resection(s) with adjustable suture for intermittent exotropia of the convergence insufficiency type

Background: The surgical results for intermittent exotropia of the converge nce insufficiency type have been reported to be of varying success. The pur pose of this study is to evaluate the surgical results of medial rectus mus cle (MR) resection(s) with adjustable suture for this condition. Methods:Tw enty-one consecutive patients with intermittent exotropia of the convergenc e insufficiency type were included in this retrospective study. All patient s had a history of prolonged difficulties at near work unrelieved by nonsur gical treatment. Unilateral or bilateral MR resection(s) were done with the adjustable suture, which was tied at the first postoperative day. The targ et angle was an esotropia of 10 to 20 PD at distance and an esotropia of 5 to 10 PD at near. Postoperatively Fresnel prisms were used temporarily in p atients manifesting a consecutive esotropia with diplopia at distance. Post operative follow-up period was between 6 months and 24 months with a mean o f 9.1 months. Results: MR resection(s) with the adjustable suture reduced t he mean exodeviation at near from 25.7 to 3 PD. It also reduced the exodevi ation at distance from 11.4 to -2 PD (esodeviation). The mean near-distance difference was collapsed from 14.3 PD preoperatively to 5 PD postoperative ly. Conclusions: MR resection(s) with adjustable suture combined with inten tional postoperative aggressive overcorrection and the use of Fresnel prism s is useful in intermittent exotropia of the convergence insufficiency type . The intentional overcorrection during the immediate postoperative period at distance and near is required to prevent long-term undercorrection.