There are few effective, safe modalities for the management of Graves' ophthalmopathy (GO), a cell-mediated immune comorbidity of thyroid disease. Somatostatin analogs inhibit lymphocyte proliferation and activation, and accumulate in the orbital tissue of patients with GO.

A double blind, placebo-controlled study of a long-acting somatostatin analog (16 weeks of Octreotide-LAR) was conducted in 51 patients with mild active GO, with the aim of preventing deterioration and precluding the need for more aggressive therapeutic modalities such as glucocorticoids or radiotherapy.

No treatment effect was observed for the primary end point (a composite parameter defining the outcome as either "success" or "failure" on the basis of changes in NOSPECS class/grade and CAS). The Clinical Activity Scale score was reduced for patients treated with Octreotide-LAR, but without any significant difference with respect to patients receiving placebo. However Octreotide-LAR significantly reduced proptosis (as measured by exophthalmometry). This was associated with non-significant differences in favor of Octreotide-LAR in a series of proptosis-related parameters: NOSPECS class III grade, opening of the upper eyelid, the difference in ocular pressure between primary position and upgaze, and extraocular muscle involvement. By MRI evaluation the extraocular muscle volumes appeared reduced, but non significantly. No significant correlation between the initial uptake of the Somatostatin analog indium-labeled and response to treatment was observed. One patient in the Octreotide-LAR group developed gallstones.

In this study, octreotide-LAR did not seem suitable to mitigate activity in mild GO. Surprisingly it significantly reduced proptosis, one of the most debilitating symptoms of GO. Further studies are warranted to define the benefit-to-risk ratio of the somatostatin analogs in this indication.