Long-term outcome of Graves' orbitopathy following high-dose intravenous glucocorticoids and orbital radiotherapy

Objective: Intravenous (iv) glucocorticoids (GC) (ivGC) and orbital radiotherapy (ORT) are commonly used in active Graves' orbitopathy (GO), with favorable outcomes in up to 80 % of patients. However, little is known on the factors that may affect GO outcome in the long term, an issue that we investigated here. Methods: We studied retrospectively 96 untreated patients with GO, identified out of 787 consecutive patients who came to our GO Clinic for a follow-up visit between September 2010 and June 2013. After the first observation, patients were treated with ivGC and ORT and were then re-examined after a median period of 55.5 months. The primary end-point was the possible relation between GO outcome and several individual variables. Results: Exophthalmometry, eyelid aperture, CAS, diplopia and visual acuity (the latter only in patients with an initial reduction) improved significantly after treatment. Overall, 67.7 % of patients had improved and were considered as responders, whereas the remaining (29.1 % stable and 4.5 % worsened) were considered as non-responders. Age, smoking, thyroid volume, thyroid treatment, serum anti-TSH receptor autoantibodies and individual GO features at first observation did not affect the outcome of GO, which, in contrast, was affected by gender and by the time elapsed between first and last observation. Thus, the prevalence of responders was higher in females (76.4 vs 48 % in males, P = 0.02) and the time elapsed between first and last observation was greater in responders (58 vs 39 months in non-responders, P = 0.02). Whereas the prevalence of responders and non-responders was similar up to 36 months, there was an increase in responders beginning between 37 and 48 months and reaching a peak of ∼80 % between 61 and 72 months, to plateau thereafter. Conclusions: Given the limitations of retrospective investigations, our study confirms that the combination of GC and ORT is effective in GO and shows that females have greater chances to respond to treatment. The notorious tendency of GO to improve spontaneously with time most likely contributes the long-term outcome of the eye syndrome.