Comparison of Surgical Results between Bilateral Recession and Unilateral Recession-Resection in 25 PD Intermittent Exotropia

ABSTRACT

PURPOSE: It is the purpose of this paper to study the long-term results of surgically treated intermittent exotropia of 25 prism diopters (PD) of preoperative deviation. METHODS: We analyzed and compared 364 patients (376 cases) with at least 6 months of postoperative follow-up. Two surgical methods were done 6 mm bilateral recession of lateral rectus muscle in 190 patients (190 cases) and unilateral 4 mm recession of lateral rectus muscle combined with 3 mm resection of medial rectus muscle in 174 patients (186 cases). RESULTS: The average age of operation was 6.2 years, ranging from 3 to 16 years, and the follow-up period after surgery ranged 6 to 128 months (mean 27.3 months). The satisfactory surgical result defined as orthophoria and deviation between 5 PD esodeviation and 10 PD exodeviation. The final success rates were 75.3% in bilateral recession group and 64.5% in unilateral recession-resection group. This difference in success rates between the two groups was statistically significant (P=0.023), and the age at operation did not influence the surgical results. Those cases who were over-corrected 6 to 10 PD had a higher success rate and there was a statistically significant relationship between alignment immediately after surgery and on the final postoperative day in the two surgical groups (P=0.0001). CONCLUSIONS: The outcome of the bilateral recession is better than that of the unilateral recession-resection for correction of 25 PD intermittent exotropia in any age group.