The color difference in orbital fat.

OBJECTIVE To identify and quantify carotenoids found in white and yellow orbital fat. METHODS Specimens of nasal (white) and preaponeurotic (yellow) orbital fat were obtained from patients during upper eyelid blepharoplasty. Carotenoids and retinoids were extracted and subjected to spectral and high-performance liquid chromatography analyses. RESULTS The chromophore content of extracts from unsaponified fat, as measured by absorbance at 425 nm per gram of fat, was 2- to 4-fold higher in preaponeurotic fat than in nasal fat. High-performance liquid chromatography analysis from enzymatically digested fat revealed large amounts of lutein, beta-carotene, and retinol and small amounts of other unidentified carotenoids. The amount of beta-carotene and lutein in preaponeurotic fat was approximately 4-fold higher than in nasal fat. CONCLUSIONS The higher carotenoid content of preaponeurotic fat might cause it to be more yellow than other orbital fat, and lutein and beta-carotene might be selectively absorbed from plasma by preaponeurotic fat. CLINICAL RELEVANCE The results provide baseline information for studies of the physiological features of orbital fat in normal and diseased conditions.