Long-Term Efficacy of Inferior Oblique Myectomy Accompanied with Tenon's Capsule Closure: Objective Analysis Using Nine-Gaze Photographs.

The aim is to evaluate the long-term efficacy of inferior oblique (IO) myectomy combined with Tenon's capsule closure to prevent muscle reattachment to the sclera. We retrospectively reviewed the medical records of 18 patients with primary and secondary IO overaction who underwent IO myectomy accompanied by Tenon's capsule closure. Patients were followed up for at least 1 year after the surgery. The main outcome measures included oblique muscle dysfunction, which was objectively graded through computerized analysis of nine-gaze photographs, and the amount of vertical deviation in the primary position using alternate prism cover testing. After a mean follow up of 2.5 years, the grade of IO overaction decreased from +2.2 ± 1.0 to -0.8 ± 1.0 ( < 0.001). In patients with secondary IO overaction with superior oblique (SO) palsy, SO underaction improved from -2.2 ± 1.5 to -0.2 ± 1.8 ( = 0.006). Successful vertical deviation in the primary position of seven prism diopters or less was achieved in 83.3% of the patients. Underaction of the IO was observed in 11.1% of patients, whereas none of the patients showed antielevation syndrome. : IO myectomy combined with Tenon's capsule closure might be safe and effective for the treatment of primary and secondary IO overaction in the long term.