Abstract:

Objective To assess the efficacy of endoscopic transethmoidal orbital wall decompression （ETMOWD） in conjunction with fat removal orbital decompression （FROD） on restrictive strabismus in patients with thyroid?associated ophthalmopathy （TAO）. Methods A retrospective case series study was conducted involving patients diagnosed with TAO at our hospital from December 2021 to August 2024. Patients were divided into two groups： the orbital decompression group （OD group） and the non?orbital decompression group （NOD group）， based on whether they underwent orbital decompression surgery. The study compared perioperative data， types of strabismus， degree of ocular motility limitation， extent of posterior migration of ocular muscles， and postoperative outcomes between the two groups. Additionally， the effects of ETMOWD combined with FROD on strabismus were evaluated by analyzing changes in relevant indices before and after surgery in the OD group. Results A total of 65 participants were included in the analysis， with 40 in the OD group group and 25 in the NOD group. There was no statistically significant difference in baseline characteristics between the two groups. Preoperative strabismus types， including horizontal and vertical strabismus， did not differ significantly between the OD and NOD groups （P > 0.05）. However， the mean preoperative restriction grade of eye movement was significantly higher in the OD group compared to the NOD group. Additionally， the number of surgeries， mean total operated muscles， and number of horizontal muscles were all significantly higher in the OD group than in the NOD group （all P < 0.05）， with a notably different effect on horizontal muscle migration between the two groups. The degree of restriction of eye movement and diplopia improved significantly in all patients， with cure rates of 70% in the OD group and 72% in the NOD group. Furthermore， the OD group underwent ETMOWD combined with FROD orbital decompression surgery， which resulted in a decrease in intraocular pressure （IOP） from （19.43 ± 3.9） mmHg preoperatively to （15.05 ± 2.2 mmHg postoperatively （P < 0.001）. Both horizontal and vertical strabismus increased after surgery. Conclusions Our results demonstrated that， compared with the NOD group， the OD group exhibited increased complexity in strabismus surgery， as evidenced by a higher number of operations， total muscle strips， horizontal muscle strips， and greater migratory effect size of the horizontal muscles. The combination of ETMOWD and FROD effectively reduced exophthalmos， with a more pronounced effect on the medial rectus muscle compared to the vertical muscles. However， the long?term outcomes between the two groups were similar.

Key words: thyroid?associated ophthalmopathy, endoscopic transethomoid medial orbital wall decompression, restrictive strabismus