Oral selenium improved the disease activity in patients with mild Graves' orbitopathy.

Background: Graves' orbitopathy (GO) is the most common extrathyroidal manifestation of Graves' disease (GD), an autoimmune disorder arising from the activity of T lymphocytes against antigens that infiltrate thyroid tissue, orbital tissue and extraocular muscles. An increase in oxidative stress has been discovered in autoimmune thyroid disease, encouraging investigation into new forms of treatment. Selenium has been described as a treatment option given its antioxidant properties. The present study evaluates the decrease of progression and inflammatory signs in patients with mild GO with oral selenium supplementation.

Methods: Controlled, randomized, single center trial at an ophthalmology referral center in Mexico City. Patients at least 18years of age with mild GO according to the CAS classification were included; exclusion criteria in addition to corticosteroid treatment included smokers or selenium allergy. Each patient was randomized into one of two groups. Group A took placebo tablets which consisted of 100μg of starch twice a day for 6months, and group B took a 100μg selenium tablet twice a day for 6months. The patients from both groups were examined and evaluated using a CAS score before and after the first, third and sixth month of treatment.

Results: Thirty eyes of 30 patients were studied. The pretreatment values showed no statistically significant differences between groups (P>0.05). Intergroup analysis showed statistically significant differences in palpebral fissure and CAS score between the pretreatment values and six months after treatment in the selenium group (P<0.05). No differences were found in any variables in the placebo group during the study period (P>0.05). No adverse events were reported.

Conclusions: This is the first study in a Mexican population demonstrating that oral selenium decreases clinical activity and stops progression in patients with mild GO.