Definition for Arcus senilis
From Biology Forums Dictionary
Arcus senilis (or arcus senilis corneae) is a white, gray, or blue opaque ring in the corneal margin (peripheral corneal opacity), or white ring in front of the periphery of the iris. It is present at birth, but then fades; however, it is quite commonly present in the elderly. It can also appear earlier in life as a result of hypercholesterolemia. Arcus senilis can be confused with the limbus sign, which reflects calcium rather than lipid deposits.
It results from cholesterol deposits in or hyalinosis of the corneal stroma, and may be associated with ocular defects or with familial hyperlipidemia. It is common in the apparently healthy middle aged and elderly; a prospective cohort study of 12,745 Danes followed up for a mean of 22 years found that it had no clinical value as a predictor of cardiovascular disease.