Change of Strabismus Angle and Deviation After Unilateral or Bilateral Lateral Rectus Recession in Exotropia

ABSTRACT

PURPOSE: To compare the changes in strabismus angle and deviation between two groups a bilateral lateral rectus recession (Group 1) and a unilateral lateral rectus recession in exotropia (Group 2). METHODS: A retrospective survey was conducted on 198 patients who had received exotropia surgery in our ophthalmology clinic from September 2003 to April 2007. A total of 116 patients were in Group 1, and 82 patients were in Group 2. RESULTS: The average deviations of the first postoperative month and the first postoperative year were -1.96 D +/- 4.75, 2.5 D +/- 7.82 for Group 1 and 0.77 D +/- 2.87, 5.94 D +/- 3.38 for Group 2. Revealing statistical significance between the 2 Groups Group 1 had 30 failure cases (25.9%) and their 1 postoperative year average deviation was 5.42 D +/- 13.97, while Group 2 showed 24 failure cases (29.3%) and their 1-postoperative-year average deviation was 13.0-79 +/- 3.04. Group 1 had less strabismus angle and a greater standard deviation than Group 2, as Group 1 had more overcorrection. Among the 30 failure cases of Group 1, 9 were overcorrected and 21 were undercorrected, but all 24 failure cases in Group 2 were undercorrected. CONCLUSIONS: The strabismus angle after lateral rectus recession showed a wider variation and a larger difference in bilateral lateral rectus recession than in the unilateral lateral rectus recession.