Dr.ATANU BARH, Dr.Kirthi Koka,Dr.M Shahid Alam,Dr.BIPASHA MUKHERJEE
Background
Thyroid eye disease is an autoimmune disorder which affects the quality of life both functionally and cosmetically. The natural history and pathogenesis is complex and governed by both endogenous and environmental factors.1 It follows a biphasic course i.e. an initial active phase of progression followed by a subsequent inactive phase.2 The majority of patients have a mild, self-limiting non progressive ocular involvement. About 3–7% of patients exhibit a severe sight-threatening disease due to compressive optic neuropathy or corneal exposure.3,4 The management of thyroid eye disease depends on activity and severity of the disease. According to the EUGOGO (European Group of Graves’ Orbitopathy) classification, the disease activity is evaluated based on clinical activity score (CAS).
A score of more than 3 is regarded as active disease in new patients and more than 4 in follow up patients.5 Interestingly, patients having clinical activity score ≤ 3 can be symptomatic and may require active intervention. Imaging assessment of disease severity in such cases can be very useful. Magnetic Resonance Imaging (MRI) is superior to Computed Tomography (CT) in these cases as it can detect active inflammation within the orbit as well as early optic nerve compression which is clinically not evident. There is paucity of literature describing the clinical profile of patients having quiescent thyroid eye disease with active inflammatory process in the orbit detected by MRI. Given this scenario, we conducted a retrospective study to evaluate the patients who had clinically inactive thyroid eye disease but had radiological activity in the orbit.
Methods
This is a retrospective interventional case series. The study followed the tenets of Declaration of Helsinki. We reviewed the records of 19 consecutive thyroid eye disease patients who had CAS ≤ 3 but had radiological activity in the orbit over a period of two years (May 2016 – April 2018). We define radiological activity as presence of T2 -hyperintense signal in one or more extraocular muscles with or without other findings including proptosis, increase fat volume and optic nerve compression. Clinical features including visual acuity, color vision, lid signs, proptosis, diploia charting, visual field test and MRI findings were noted in all patients.
Results:
Total 19 patients were included in this study with a mean age of 51.6 ± 11.4 year at presentation. Out of 19 patients 12 were female and 7 were male. Bilateral disease was seen in 10 patients (52.6%), whereas 9 patients (47.4%) had unilateral involvement. Thyroid status revealed hyperthyroidism in 10 patients (52.6%), hypothyroidism in 5 patients (26.4%) and euthyroid state in 4 patients (21%). History of smoking was present only in 2 patients. Ten patients (52.6%) presented with both proptosis and diplopia; 6(32.6%) had only proptosis; 3(15.8%) had only diplopia.
Ocular motility limitation was found in 16 patients (84.2%). Seven patients (36.8%) had manifest squint as presentation. Two patients showed optic nerve compression on MRI. One of them had normal visual acuity and colour vision. All patients were advised for external beam radiotherapy under intravenous steroid cover except one young female who had mild unilateral proptosis without diplopia. In view of young age (30 years), the patient was not advised for radiotherapy and was kept under close follow up. Ten out of 18 patients underwent bilateral external beam radiotherapy of 20 Gy in 10 fractions with concurrent intravenous methyl prednisolone of 500mg. None of the patients showed any immediate radiation related complication.
Discussion
Activity of thyroid eye disease refers to the inflammatory process. It is essential to differentiate it from the severity of the disease which refers to the quality of life or the risk of vision loss.6 In practise, activity of thyroid eye disease is determined by CAS score or VISA score (Vision, Inflammation, Strabismus and Appearance). The major drawback of these scoring systems is lack of treatment guidelines. Active management of thyroid eye disease depends on patients’ functional and cosmetic appearance irrespective of clinical activity score. Moreover, CAS does not always correlate the underlying inflammatory process in the orbit.
Active inflammatory process in the orbit can be confirmed by MRI scan. In this present study we described 19 symptomatic thyroid eye disease patients where clinical activity score was ≤ 3. All of them had active inflammation in the orbit confirmed by MRI scan. There is lack of consensus regarding management in such cases. Safety and efficacy of intravenous methyl prednisolone and low dose external beam radiotherapy (20Gy) in moderate to severe thyroid eye disease are already established.7,8,9,10,11 Intravenous steroid has faster onset of action compared to radiotherapy but duration of action is less. We preferred combined treatment with radiation and intravenous methyl prednisolone for a faster and sustained response.
Conclusion
Radiologically active thyroid disease should be considered as a separate entity. Imaging in the form of MRI should be considered in early symptomatic TED patients as a baseline investigation as radiologically active thyroid eye disease may need active intervention irrespective of clinical activity score. Long term follow up is required to assess the course of disease as well as management outcome in such patients.
References
- Wang Y, Smith TJ. Current concepts in the molecular pathogenesis of thyroid-associated ophthalmopathy. Invest Ophthalmol Vis Sci. 2014; 55(3):1735-48.
- Douglas RS G S. The pathophysiology of thyroid eye disease: implications for immunotherapy. Curr Opin Ophthalmol. 2011 Sep; 22(5):6.
- S. Bahn. Graves’ ophthalmopathy. The New England Journal of Medicine. 2010; 362(8): 726–738.
- J. Dolman. Evaluating Graves’ orbitopathy. Best Practice & Research Clinical Endocrinology&Metabolism. 2012; 26(3): 229–248.
- P.Mourits, M. F. Prummel,W.M.Wiersinga, and L. Koornneef. Clinical activity score as a guide in the management ofpatients with Graves’ ophthalmopathy. Clinical Endocrinology. 1997; (47): 9–14.
- M. Wiersinga, P. Perros, G. J. Kahaly et al. Clinical assessment of patients with Graves’ orbitopathy: the European Group on Graves’ Orbitopathy recommendations to generalists, specialists and clinical researchers. European Journal of Endocrinology. 2006; 155(3): 387–389.
- Bahn. High-dose intravenous glucocorticoid therapy for Graves’ ophthalmopathy: where are we now? Thyroid. 2012; 22(1): 1–2.
- Zhu, L. Ye L. Shen et al. A prospective, randomized trial of intravenous glucocorticoids therapy with different protocols for patients with graves’ ophthalmopathy. The Journal of Clinical Endocrinology&Metabolism. 2014; 99(6): 1999–2007.
- J. Dolman and S. Rath. Orbital radiotherapy for thyroid eye disease. Current Opinion in Ophthalmology. 2012; 23(5): 427–432.
- Johnson KT, Wittig A, Loesch C, et al. A retrospective study on the efficacy of total absorbed orbital doses of 12, 16 and 20 Gy combined with systemic steroid treatment in patients with Graves’ orbitopathy. Graefes Arch Clin Exp Ophthalmol. 2010; 248:103–9.
- L. Tanda and L. Bartalena. Efficacy and safety of orbital radiotherapy for graves’ orbitopathy. Journal of Clinical Endocrinology and Metabolism. 2012; 97(11): 3857–3865.


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