Comparison of Outcomes of Unilateral Lateral Rectus Recession for Exotropia between First and Second Operations

PURPOSE To compare the outcomes of unilateral lateral rectus recession between the first operation and second operation for exotropia. METHODS Thirty-two patients who underwent unilateral lateral rectus recession for exotropia of 15 to 20 prism diopters (PD) were investigated. The follow-up period was at least 6 months. We classified 17 patients without a surgical history for exotropia (first operation group) and 15 patients with a previous procedure (second operation group). Surgical success was defined as an exodeviation or esodeviation of less than 10 PD at the primary position. Postoperative deviation angles and success rates were compared between the two groups. RESULTS There were no significant differences in the age, gender, visual acuity (logarithm of the minimal angle of resolution), preoperative deviation, and amount of recession between the two groups. Postoperative deviations were -1.7 ± 5.5:1.3 ± 5.1 PD at one day, 4.3 ± 3.8:5.6 ± 5.1 PD at 1 month, 4.3 ± 4.3:3.0 ± 8.1 PD at 3 months, and 5.0 ± 4.3:4.5 ± 7.2 PD at 6 months post-operation, and there was no statistically significant difference between the two study groups. Surgical success rate were 95.2:100% at one day, 95.2:92.9% at 1 month, 90.5:85.7% at 3 months, and 90.0:92.9% a 6 months post-operation. CONCLUSIONS In patients with exotropia of 15 to 20 PD, no significant difference was found in terms of the postoperative deviation angle and the surgical success rate between the first operation and the second operation groups. Unilateral lateral rectus recession can lead to similar results in 15 to 20 PD exotropia for the first operation or recurrent exotropia.