Arched rainbow brow: A new clinical trait that can help diagnose thyroid eye disease

U.S.A: According to a study published in the journal Ophthalmic Plastic & Reconstructive Surgery, the rainbow brow is a novel clinical characteristic caused by brow fat pad growth that may be helpful for diagnosing thyroid eye illness.

An uncommon condition known as thyroid eye disease causes tissues around the eyes to progressively swell and deteriorate, particularly the extraocular muscle, connective tissue, and fatty tissue. The identification of distinctive symptoms, a complete patient history, a comprehensive clinical evaluation, and a variety of specialist tests are used to make a diagnosis of thyroid eye disease. A physical examination can diagnose thyroid eye disease based on a few signs that are frequently visible.

An innovative clinical aspect of thyroid eye illness was to be described morphologically and statistically in this study (TED) by the authors.

Retrospective research on TED patients and age- and sex-matched healthy controls was done for this objective. A total of 271 eyes were examined (200 TED and 71 age-sex-matched normal controls). Three oculoplastic surgeons came to consensus on the arched Rainbow Brow appearance in TED patients. Plotting 15 points along the eyebrow in ImageJ allowed the researchers to determine the eyebrow's curve. Each eyebrow was fitted with the fourth-degree polynomial (y = ax4 + bx3 + cx2 + dx + e).

Key points of the study:

• In 42% of TED patients, a Rainbow Brow was found.
• In 15% of patients, a unilateral Rainbow Brow was observed.
• For the coefficients a, b, c, and d of the fourth-degree polynomial, there were substantial differences among Rainbow Brow patients and age- and sex-matched normal controls.
• Coefficients a and b differed between TED patients with and without Rainbow Brows in analyses of a similar nature.
• The occurrence of a Rainbow Brow was associated with age >50 years (p = 0.009) and brow fat expansion (p <0.001).
• A Rainbow Brow appeared to be associated with proptosis more than 24 mm (p = 0.057).
• In a multivariable analysis where these features were taken into account, only the increase of brow fat was found to be a significant contributing factor (p = 0.009).

In contrast to both typical age-sex-matched controls and TED patients without a Rainbow Brow, individuals with a Rainbow Brow have a distinct brow curve, the investigation concluded.

REFERENCE

Tran, Ann Q. M.D.*,†; Yang, Cameron M.D.‡; Tooley, Andrea A. M.D.§; Mahan, Marielle M.D.∥; Jamerson, Emery C. M.D.*; Kazim, Michael M.D.*; Dagi Glass, Lora R. M.D.*. The Arched Rainbow Brow in Thyroid Eye Disease. Ophthalmic Plastic and Reconstructive Surgery: September/October 2022 - Volume 38 - Issue 5 - p 469-474 doi: 10.1097/IOP.0000000000002168