[The surgical effect of secondary esotropia with diplopia after orbital decompression for thyroid-associated...

Objective: To evaluate the effect of extraocular muscle surgery in treating secondary esotropia with diplopia after orbital decompression for thyroid-associated ophthalmopathy (TAO). Methods: Retrospective case series study. Eleven secondary esotropic patients with diplopia after orbital decompression for TAO who underwent extraocular muscle surgery during March 2016 and October 2018 in Tianjin Eye Hospital were included. All patients had new onset esotropia after decompression surgery and underwent strabismus surgery. Deviation angle, diplopia, and ocular movement were observed preoperatively and postoperatively. Surgeries were carried out under the monitored anesthesia care combined with local anesthesia, and the eye alignment was adjusted to orthotropia with no diplopia in the operation with the technique of intraoperative adjustable suture and forced duction test results. All the patients were followed up. Results: The ages of the patients were from 26 to 42 years (1 male and 10 females). The deviation angles were 10-98 prism diopter. Orbital CT scan showed that the horizontal rectus thickness was increased at different levels, and the thickness of the medial rectus was increased more than that of the lateral rectus. Two patients had monocular medial rectus recession only, 2 had bilateral medial rectus recession only, 2 had monocular medial rectus recession combined with lateral rectus resection, and the other 5 had bilateral medial rectus recession with monocular lateral rectus resection. The recession of medial rectus muscle was 3.5 to 7.5 mm in 11 patients and 2.0 to 6.0 mm in 7 patients with the resection of lateral rectus muscle. Diplopia of the 11 patients disappeared with orthotropia at primary gaze position after the extraocular muscle surgery. The limitation of abduction changed from preoperative (-1.91±1.04) to postoperative (-0.64±0.81). All the patients were satisfied with the surgical results. At the end of the follow-up (6 to 24 months), the results of the patients were stable, and no over-correction was found. Conclusion: Extraocular muscle surgery with intraoperative adjustable suture technique can effectively treat TAO patients with secondary esotropia with diplopia after orbital decompression. (Chin J Ophthalmol, 2020, 56: 183-188).