A Randomized Clinical Trial Comparing Myectomy and Recession in the Management of Inferior Oblique Muscle Overaction

Abstract

It is still not clear whether inferior oblique recession or inferior oblique myectomy is a better option for weakening inferior oblique overaction (IOOA). The aim of this study was to compare the effect of these two methods on IOOA. Patients who were candidates for surgical management of IOOA were randomly assigned to either IO myectomy or recession. Complete ophthalmic examinations were performed before surgery. In the myectomy group, 5 mm was excised from the inferior temporal region of IO muscle(s). In the recession group, the IO muscle was disinserted and subsequently sutured to a point 2 mm lateral and 4 mm posterior to the insertion of the inferior rectus muscle on the temporal side. Satisfactory results were defined as an IO function of grade 0 or 1+ at 3 months postoperatively. The study included 50 patients (82 eyes) with a mean age of 12.3 ± 5.9 years (range: 3 to 32 years). Both methods were effective on the weakening of IOOA (P < .001). The rate of satisfactory results was similar in both groups (P = .686). The rate of residual IOOA and IO underaction did not differ between the two groups. Regarding the changes of horizontal or vertical deviations, V pattern, and dissociated vertical deviation, there was no statistically significant difference between the two groups. For treatment of IOOA, both IO myectomy and recession can be used with similar success rate.