The Arched Rainbow Brow in Thyroid Eye Disease

Area of Science:

• Ophthalmology
• Medical Imaging
• Plastic Surgery

Background:

• Thyroid eye disease (TED) is an autoimmune condition affecting the orbit.
• Clinical manifestations of TED can include proptosis and eyelid retraction.
• Novel morphological features in TED require detailed description and quantification.

Purpose of the Study:

• To describe and mathematically quantify a newly identified clinical feature in thyroid eye disease, termed the Rainbow Brow.
• To investigate the association between the Rainbow Brow and other clinical parameters in TED patients.

Main Methods:

• Retrospective analysis of 200 TED patients and 71 age-sex-matched controls.
• Identification of the Rainbow Brow appearance by a panel of oculoplastic surgeons.
• Quantitative assessment of eyebrow curvature using ImageJ and fitting a fourth-degree polynomial to 15 plotted points.

Main Results:

• A Rainbow Brow was present in 42% of TED patients.
• Significant differences in polynomial coefficients (a, b, c, d) were found between TED patients with and without a Rainbow Brow, and compared to controls.
• Brow fat expansion was significantly associated with the presence of a Rainbow Brow (p < 0.001).

Conclusions:

• The Rainbow Brow is a distinct clinical entity in thyroid eye disease.
• Brow fat pad expansion is the likely cause of the Rainbow Brow.
• Patients with a Rainbow Brow exhibit altered eyebrow curvature compared to controls and TED patients without this feature.