Haiyang Zhang,1,* Mengda Jiang,2,* Yuting Liu,1,* Xin Ning Lee,1 Zilin Fang,1 Jipeng Li,1 Yinwei Li,1 Jing Sun,1 Xiaofeng Tao,2 Xuefei Song,1 Huifang Zhou,1 Xianqun Fan1 

1State Key Laboratory of Eye Health, Department of Ophthalmology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2Department of Radiology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xianqun Fan, Email fanxq@sjtu.edu.cn Huifang Zhou, Email fangzzfang@sjtu.edu.cn

Purpose: To investigate the alterations in the glymphatic system in patients with thyroid eye disease (TED) using diffusion tensor imaging (DTI) analysis along the perivascular space (ALPS) and to explore the correlation between the glymphatic system and clinical features of TED.
Methods: The study included 47 patients with TED, including 20 active TED patients (AP) and 27 inactive TED patients (IP), along with 24 healthy controls (HC). Imaging data including DTI sequence were acquired using a 3.0 Tesla scanner. ALPS values were calculated based on the diffusivity of the bilateral superior corona radiata and superior longitudinal fasciculus. Correlation analysis were thus performed between ALPS values and clinical characteristics.
Results: The DTI-ALPS analysis in the TED patient group collectively showed lower mean and left ALPS values compared to the HC, with statistically significant differences observed (mean ALPS: P=0.0308, left ALPS: P=0.0032). Among the TED subgroups, the IP had significantly lower left ALPS values than HC (P=0.006). Correlation analysis within the IP subgroup indicated that lower ALPS values were significantly associated with longer disease duration (P=0.015) and greater palpebral fissure height (P=0.028).
Conclusions: Glymphatic system dysfunction is evident in TED patients, with its extent influenced by disease activity and duration.

Keywords: thyroid eye disease, glymphatic system, diffusion tensor imaging along the perivascular space, magnetic resonance imaging, disease activity