Context: Despite a strong rationale for trials of somatostatin analogs in the treatment of Graves' ophthalmopathy (GO), recent studies have provided conflicting results.

Objective: To determine whether octreotide long-acting release (LAR) is effective treatment for active GO.

Design: Prospective, randomized, double-blind, placebo-controlled study.

Setting: Single tertiary referral center.

Patients: 29 consecutive euthyroid patients with active GO [clinical activity score (CAS) 3] were enrolled; 25 completed the study.

Intervention: Patients received 4 monthly doses of either octreotide-LAR (20 mg) or saline by intramuscular injections.

Main Outcome Measures: Primary: change in CAS; secondary: changes in retrobulbar tissue volume, proptosis, lid fissure width, range of motion, diplopia fields.

Results: Median (range) CAS change was 2.5 (1, 5) in the treatment and 1.0 (0, 7) in the placebo group (P = 0.02). Median lid fissure width improved in the treatment group (decreased 1 mm on the right and 0.5 mm on the left) compared with the placebo group (no change on the right, P < 0.01; increased 1 mm on the left, P < 0.01). No other significant differences between groups were identified.

Conclusion: CAS improved to a greater extent in octreotide-LAR treated patients than in the control group. However, this finding may not represent clinical benefit as patients with higher baseline CAS were over-represented in the treatment group and the control group was small. In contrast, treatment-related improvement in eyelid fissure width was noted, suggesting that octreotide-LAR may be useful in the treatment of a subgroup of active GO patients with significant lid retraction.