Abstract: Objective To observe the surgical outcome of bilateral lateral rectus recession in children with simulated divergence excess intermittent exotropia. Methods Twenty-two children with simulated divergence excess intermittent exotropia underwent bilateral lateral rectus recession from December 2010 to August 2013 were recruited in this study. The exodeviations were measured by the alternate prism cover test at both distances (6 m and 33 cm) with fixation on accommodative targets before and after 1-hour diagnostic occlusion test. The Worth 4-Dot test was employed to assess central and peripheral fusion. The Titmus stereo test was used to assess stereoacuity. The target angle for the symmetrically quantitative bilateral lateral rectus recession was determined according to the largest distance deviation before or after diagnostic occlusion test. The examinations were carried out on the first postoperative day, 1 months, 3months and 6 months later. A successful alignment was defined as ±8 PD or less in primary gaze while viewing distant and near targets. Results The average age of patients was 6.3±2.9 years. The disparity between distance deviation and near deviation before and after diagnostic occlusion test was 17.3±7.9 PD and 0.5±3.3 PD, respectively. The amount of bilateral lateral rectus recession was 7.2±1.2 mm. Mean postoperative follow-up period was 8.6±5.4 months. The successful rate, overcorrection rate, undercorrection rate at the end of follow-up was 81.8%(18 in 22), 4.5%(1 in 22), 13.6%(3 in22), respectively. There was no significant difference in fusion and stereoacuity before and after surgery (P>0.05). Conclusion Based on the largest distance deviation before and after diagnostic occlusion test, bilateral lateral rectus recession could effectively treat simulated divergence excess intermittent exotropia in children.

Key words: Exotropia,intermittent, Opthalmologic surgical procedures, Treatment outcome, Lateral rectus recession, bilateral, Child, Simulated divergence-excess type