Different Characteristics of Orbital Soft Tissue Expansion in Graves Orbitopathy: Extraocular Muscle Expansion is Correlated to Disease Activity While Fat Tissue Volume With Duration

Abstract

This study aimed to describe the correlation between some clinical features and orbital soft tissue volume in Graves orbitopathy (GO). The authors collected computed tomography scans from 56 untreated GO patients and measured fat volume (FV), intraorbital and extraorbital FV (IFV, EFV), bony cavity volume (BV), and extraocular muscle volume (MV) of the 112 orbits by using Mimics software. The ratio of soft tissue volume and BV were used to eliminate the individual variations. Outcomes were compared among groups and were correlated with clinical data, including age, sex, clinical activity score, duration, serum TSH receptor antibody (TRAb) level, body mass index and smoking status. Multivariate linear regression showed that higher MV/BV is associated with higher CAS and TRAb level (P<0.001, 0.005, respectively). No relationship was found between MV/BV and duration, sex, age, and body mass index. IFV/BV was related to duration (β=0.138, 95% confidence interval: 0.076–0.201, P<0.001), and did not correlate to clinical activity. IFV and MV are positively associated with exophthalmometry (P=0.009, <0.001, respectively), while orbital bony volume (BV) is negatively correlated with exophthalmometry (P=0.025). Results suggested TRAb level can impact the severity of GO mainly by affecting extraocular muscle rather than fat tissue. MV of GO is associated with disease activity, whereas IFV is correlated with duration and increases over time.

Deep-Learning Based Automated Segmentation and Quantitative Volumetric Analysis of Orbital Muscle and Fat for Diagnosis of Thyroid Eye Disease

“…There was significant variation in muscle volumes across the three categories ( P < 0.0003), with a notable progressive increase in volumes from normal healthy patients to patients with mild and severe TED, in alignment with muscle volume changes in other studies. 7 , 9 , 20 In contrast, the average orbital fat volumes were statistically significant for normal, mild TED, and severe TED for male patients ( P < 0.003), but not for female patients. The fat volumes also did not progressively increase, and the patients with mild TED trended toward having higher fat volumes than patients with severe TED.…”

Orbital lymphocyte populations in three states of thyroid eye disease

“… 20 Within the orbit, the primary site of inflammation in TED is not only the orbital fat but also the extraocular muscles, where lymphocytes mediate elaboration of connective tissues by fibroblasts. 6 , 7 Although orbital fat often lacks lymphocytic infiltrate 6 , 7 and TED may be primarily driven by muscle expansion, 21 markers of inflammation including T-cell-derived cytokines found there may be key drivers of TED. 3 , 22 Our finding that all three samples of orbital fat in various states of TED were devoid of lymphocytic infiltration excluding perivascular cuffs is, therefore, consistent with previous histopathological analysis.…”

Interrater reliability of photographic assessment of thyroid eye disease using the VISA classification

“…One of the first monoclonal antibodies, teprotumumab, has been FDA-approved for the treatment of TED based on interventional trials [ 8 , 9 , 12 ]. One key aspect of conducting treatment trials in TED and to monitor treatment response in clinical care, is to ensure the parameters used to define treatment response are reliable and reproducible [ 13 ].…”