Endocrine Abstracts

Radioidine (RI) has been implicated as an adverse factor causing deterioration of Thyroid-Associated Ophthalmopathy (TAO). Oral steroids administered after RI appear to protect patients' eyes, and this practice is now widespread. Two factors may confound the controversy surrounding the effects of RI on TAO. Firstly hypothyroidism, which is common after RI and is independently detrimental to the eyes, and secondly studying patients who are in different phases of the natural history of TAO at the time of RI therapy.
Our hypothesis was that by selecting patients with inactive eye disease and by preventing hypothyroidism, potential detrimental effects of RI could be eliminated.
Sixty-five patients showed clinically inactive (clinical activity score (CAS)< 3) but significant TAO (55% NOSPECS > 4). All were on antithyroid drug therapy for hyperthyroidism due to Graves' disease, and were assessed before a 400 MBq dose of RI, and again at 2,4 and 6 months post therapy. Assessments comprised of symptom questionnaire, clinical activity score (CAS), soft tissue inflammation; exophthalmometry; palpebral fissure width; eye motility; cornea; optic nerve function.
No significant changes were found in eye-related symptom scores. The CAS declined significantly at 6 months (0.82 +/-1.1SD to 0.28+/-0.68SD, p=0.001). Soft tissue inflammation scores declined and the difference reached significance at 6 months (3.2+/-SD3.3 to 2.4+/-SD3.1, p=0.028). Exophthalmos improved significantly at 6 months (19.46+/-SD2.4 to 19.1+/-SD2.4, p=0.025). Palpebral fissure width improved significantly at 4 months (10.94+/-SD7 to 10.62+/-SD1.6, p=0.02). Other parameters showed no change.
In summary, the features of TAO did not deteriorate after RI. Small improvements in soft tissue inflammation, exophthalmos and palpebral aperture were noted.
We conclude that prophylactic steroids are unnecessary in patients with TAO who have inactive eye disease and are maintained euthyroid with early thyroxine replacement therapy.