The "Quiet TED"-A Special Subgroup of Thyroid Eye Disease.

Purpose: Thyroid eye disease (TED) or Graves' orbitopathy starts with an active inflammatory stage (active disease) followed by resolution of inflammation and progression to a fibrotic, inactive stage. In our practice, we have encountered cases that have not had active disease despite presence of fibrotic sequelae and disease progression. We aim to delineate the clinical characteristic of this unique group of patients.

Methods: We conducted a single-center (Mayo Clinic Rochester) retrospective chart review of TED patients who throughout the course of their disease had only evidence for inactive TED, defined as clinical activity score <3.

Results: Median age in the cohort (n = 19) was 54 years (IQR 47-61). 58% had a prior diagnosis of Graves' disease (GD) before referral. 80% (n = 15) were euthyroid at the time of TED onset (median thyroid-stimulating hormone 1.7 mIU/L). The most common finding was diplopia (100%, n = 19) followed by proptosis (63%, n = 12). Interestingly the disease was asymmetric in 42% of cases. Overall median clinical activity score on presentation was 1 (IQR 0-1). Severity wise, 85% (n = 16) of patients were classified as moderate-to-severe during follow up. Orbital decompression was performed in only 1 case, while extraocular muscle surgery was performed in 13 cases.

Conclusions: Quiet TED is a subgroup of TED patients that defies the classic disease paradigm. It presents primarily with diplopia and proptosis. Further evaluation of this group might identify useful insights in TED pathophysiology and help optimize therapeutic choices.