Factors associated with severity of orbitopathy in patients with Graves' disease

Graves' orbitopathy (GO) is one of the most frequent orbital disorders and is the most common cause of proptosis in adults. GO is described as chronic inflammation of orbital and periorbital tissues. This study aimed to evaluate the risk factors for severe GO in patients with Graves' disease (GD).

This was a prospective cross-sectional study done on 52 newly diagnosed patients of GD with GO documented by thyroid ^99mTechnetium-pertechnetate scan at our center between May 2016 and May 2019. All patients underwent a comprehensive ophthalmological examination and laboratory and hormonal analysis. Clinical Activity Score (CAS) and severity were estimated as per the European Group on Graves Orbitopathy. Thirty-four patients with mild GO were compared with 18 patients with moderate-to-severe GO (severe) for baseline risk parameters.

Majority of the patients had mild orbitopathy (34 [65.4%]) followed by moderate to severe (18 [34.6%]). CAS was active in 13.5% of the study group. There was a statistically significant male preponderance in severe GO. Current smoking increased the risk of severe GO (P = 0.003). Duration of GD symptoms at presentation was statistically significantly longer in severe GO patients than mild GO (P = 0.004). Thyrotropin receptor antibody (TRAb) titer significantly increased in severe GO group (6.2 ± 2.4 IU/L) when compared to mild GO (3.2 ± 1.6 IU/L) (P < 0.001). TRAb positivity was similar between groups. Braley's sign, i.e., the differential intraocular pressure (IOP) of >6 mmHg, was statistically significantly higher in severe GO (P < 0.001). Male gender, current smoking, TRAb >2 upper limit of normal (ULN), and differential IOP >6 mmHg were found to be associated with severe GO.

Approximately 35% of the patients with GO have severe disease, with a higher risk in men. This study identified male gender, current smoking, TRAb >2 ULN, and differential IOP >6 mmHg to be associated with severe GO.