Self-grading effect of inferior oblique recession

Purpose: Inferior oblique (IO) myectomy can result in self-adjustment; the greater the preoperative hyperdeviation, the larger the postoperative correction. This study estimated the eff ect of IO recession in primary position and in contralateral gaze. Methods: Records of 43 patients with IO muscle overaction associated with congenital unilateral superior oblique palsy were reviewed retrospectively. Seventeen patients who had a unilateral 10-mm recession (IO attached at 2 mm temporal and 3 mm posterior from the inferior rectus muscle insertion) and 26 patients who had a standard 14-mm recession were evaluated at 3 months postoperatively. The eff ect of the recession was measured by preoperative hyperdeviation minus postoperative hyperdeviation. Results: The average preoperative hyperdeviation was 13.4 ± 4.83 prism diopters (PD) in primary position and 16.2 ± 6.32 PD in contralateral gaze in the 10-mm group and 8.0 ± 3.48 PD in primary position and 12.76 ± 4.55 PD in contralateral gaze in the 14-mm group. The average deviation at 3 months postoperatively was 2.1 ± 3.03 in primary position and 2.6 ± 3.95 PD in contralateral gaze in the 10-mm group and 0.8 ± 1.21 in primary position and 1.8 ± 1.95 PD in contralateral gaze in the 14-mm group. The range of self-adjusting eff ect at 3 months postoperatively was 3 to 20 PD in primary position and 5 to 30 PD in contralateral gaze in the 10-mm group and 3 to 15 PD in primary position and 4 to 24 PD in contralateral gaze in the 14-mm group. The selfgrading eff ect was large and displayed no significant diff erences at 3 months postoperatively in the 10- and 14-mm groups (P = .104 and .560, respectively). Conclusion: Both IO recession procedures were largely self-grading and no significant diff erences were evident at 3 months postoperatively.