Subclinical ocular alterations in thyroid eye disease. An additional score to predict the progression of disease.

Abstract

Purpose: To evaluate if specific subclinical ocular signs, in association with thyroid function and thyroid antibody levels, are predictive of the progression of thyroid eye disease (TED).

Methods: Thirty-seven patients with TED (30 female) were retrospectively studied at baseline and at 1 year. They were classified according to the Clinical Activity Score (CAS) published by the EUropean Group of Graves' Orbitopathy and were asymptomatic for active TED (CAS ≤ 2) and diplopia. An additional clinical score was also used for these patients, which incorporated some signs used in the CAS protocol (active lid sweeling, eyelid erythema, definitive conjunctival redness, chemosis caruncle or plical infiammation) with the following additional signs: extraocular muscle alteration, increased intraocular pressure in upgaze and the red lens test. This new clinical score awards one point for each of these signs. This score was compared to the CAS. All patients were evaluated at baseline and at 1 year.

Results: At baseline, 19 patients were CAS 0, with no symptoms of TED, 15 patients were CAS 1 and 3 patients were CAS 2. At this time 16/37 (43.2%) patients were in subclinical hyperthyroidism and the remaining 21/37 (56.8%) were euthyroid, under antithyroid drug therapy or after a thyroid definitive cure. At follow up, 31 patients were euthyroid and 6 patients were in subclinical hyperthyroidism. Using the additional scoring system, at baseline 2/37 (5.4%) patients had no additional signs, 11/37 (29.7%) had one additional sign, 9 (24.3%) had two additional signs, 10/37 (27.1%) had three additional signs and 5/37 (13.5%) had 4 additional signs. Four out of the 5 patients with 4 additional signs developed active TED and required intravenous pulsed methylprednisolone and radiotherapy.

Conclusions: According to this additional clinical score, patients scoring 0 - 1 have a low risk of worsening CAS; they may become worse if thyroid function is altered or if thyroid autoantibody levels are elevated. Patients who score 2-3, may improve their CAS if they are euthyroid or have low thyroid antibody levels. They may become worse if they have subclinical hyperthyroidism or elevated thyroid autoantibody levels. Patients who score 4 are at high risk of a deteriorating CAS. This preliminary study indicates that the presence of these additional subclinical ocular signs may be predictive of the development of active TED

Keywords: 722 strabismus • 522 eye movements • 515 esotropia and exotropia