Evaluation of change in objective cyclotorsion after various inferior oblique-weakening procedures.

PURPOSE:To study the effect of four types of inferior oblique-weakening procedures on ocular torsion: inferior oblique recession (IOR), recession and antero-positioning (RAP), anterior transposition as practiced by Elliot and Nankin (EN), and anterior and nasal transposition (ANT). METHODS:The medical records of 72 consecutive patients >10 years of age undergoing inferior oblique weakening for primary or secondary inferior oblique overaction (IOOA) with or without horizontal rectus surgery were reviewed retrospectively. The 106 included eyes were assigned to one of the four groups according to the type of inferior oblique-weakening procedure. The severity of IOOA and the amount of V pattern guided the choice of procedure. IOOA, disk-fovea angle (DFA), and the amount of V pattern were recorded preoperatively. Measurements were repeated postoperatively at 1 week, 4 weeks, and 3 months. Change in the DFA was used to study the change in objective cyclotorsion in all four groups. RESULTS:A significant incyclotorsional shift was seen in all four groups at postoperative 3 months. The mean reduction in excyclotorsion 3 months postoperatively was 3.65° ± 4.84° for IOR, 5.31° ± 4.64° for RAP, 6.10° ± 3.89° for EN, and 16.62° ± 8.72° ANT; it was significantly higher in the ANT group compared with the other three groups. Reduction in DFA was also correlated with preoperative DFA overall, and for all procedures except IOR (P ≤ 0.005). CONCLUSIONS:All four inferior oblique-weakening procedures reduced excyclotorsion; the largest reductions in our study were seen in cases treated using ANT of the inferior oblique.