Involvement of the eyebrow fat pad in Graves' orbitopathy.

Involvement of the eyebrow fat pad in Graves' disease has never been reported. We noted that Graves' orbitopathy patients had bulkier eyebrows due to a larger eyebrow fat pad not associated with the preaponeurotic fat. A cadaver model was used to show that the eyebrow fat could be identified with magnetic resonance imaging (MRI) scans. Then, a series of Graves' orbitopathy patients were sent for orbital MRI scans, and the eyebrow fat was measured with maximum lengths and widths. The averages were compared to two groups of patients, one without orbital pathology, and one with orbital pathology causing proptosis but not due to Graves' disease. Graves' patients with early orbitopathy and incipient optic neuropathy or congestive orbits where optic neuropathy had to be ruled out had statistically significant larger eyebrow fat pads than either comparison group. This has clinical significance: The eyebrow fat may need to be debulked during operations such as blepharoplasty. Furthermore, periorbital fat may play a larger role in the disease process than previously thought.