Objective: To compare the surgical efficiency of unilateral recession-resection and slanted medial rectus (MR) resection for convergence insufficient exotropia.Methods: In this prospective study, 36 patients with exotropia of convergence insufficiency treated in the ophthalmic center of the First Affiliated Hospital of
Zhengzhou University from September 2016 to February 2017. Patients were divided into three groups according to different surgical procedures including unilateral recession-resection (Group A, 16 cases),unilateral slanted MR resection (Group B, 9 cases), and bilateral slanted MR resection (Group C, 11 cases).In Group A, the amount of MR resection was based on the near deviation, and the amount of lateral rectus (LR) recession was based on the distant deviation. In Groups B and C, the upper edge of the MR was resected according to the distant exodeviation, and the lower edge of the MR was resected according to the near exodeviation. Successful outcome was defined as a postoperative residual deviation at a distance of ±10 △ . The proportion of postoperative success, the postoperative deviations at near and distant field, and the difference between near and distant field among the three groups were compared. results: At the final follow-up examination, the proportion of success in Group A (14/16 cases) was significantly higher than in Group B (2/9 cases) and Group C (4/11 cases) (P < 0.05). The mean deviation at near and distant in Group A was significantly lower than in Groups B and C (P < 0.05). There were no significant differences in the near and distant deviation among the three groups. conclusions: Unilateral recession-resection in which the MR resection is made according to the near deviation and the LR recession according to the distant deviation can successfully treat exotropia of convergence insufficiency better than the slanted MR resection.