PURPOSE: To gauge the efficacy and safety of performing a one-stage endoscopic orbital decompression procedure combined with the intraoperative relaxed medial rectus muscle (MR) positioning technique as a means of treating esotropia associated with thyroid-associated ophthalmopathy (TAO). DESIGN: Prospective, single-blind, randomized controlled trial. SETTING: Eye Hospital of Wenzhou Medical University. METHODS: 38 TAO patients fulfilled the study requirements. The patients in Group A (n=19
mean age 52.32 ± 9.90 years
12 males, 7 females) underwent a one-stage surgical procedure, whereas the patients in Group B (n=19
mean age 52.53 ± 8.49 years
9 males, 10 females) underwent staged surgery. Preoperative and postoperative best-corrected visual acuity (BCVA), visual field mean deviation (MD), Hertel exophthalmometry, intraocular pressure (IOP), deviation, ocular motility, and diplopia were compared between these two groups. RESULTS: Of the patients in Group A, 8 (42.11%) underwent unilateral orbital decompression and 11 underwent bilateral decompression, while all 19 patients in Group B underwent bilateral decompression. Both groups exhibited significant improvements in postoperative BCVA (Group A 0.09 ± 0.15 logMAR, Group B 0.04 ± 0.08 logMAR), MD of visual field (Group A -2.73 ± 3.36 dB, Group B -1.82 ± 3.75 dB), proptosis (Group A 16.23 ± 2.58 mm, Group B 17.04 ± 2.70 mm), and IOP (Group A 16.23 ± 4.49 mmHg, Group B 17.24 ± 4.14 mmHg) when comparing postoperative values to preoperative levels, while there were no significant differences between these groups. In each group, 8 patients (42.11%) underwent surgical procedures targeting one single MR, whereas the remaining 11 in each group underwent surgery on two MRs. The respective primary motor and sensory success rates in Group A were 68.40% (13/19) and 78.95% (15/19), whereas those in Group B were 73.70% (14/19) and 84.21% (16/19), with no significant differences between these groups in terms of postoperative residual strabismus, stereoscopic vision improvements, or success rates. CONCLUSION: These results demonstrate that a one-stage surgical procedure can simultaneously alleviate proptosis and diplopia while achieving outcomes comparable to those achieved through staged surgery. This treatment strategy can thus provide patients with greater therapeutic convenience, decreasing the overall number of surgical procedures and their attendant risks.