Arcus senilis

Arcus senilis
Four representative slides of corneal arcus - arcus deposits tend to start at 6 and 12 o'clock and fill in until becoming completely circumferential. There is a thin, clear section separating the arcus from the limbus, known as the lucid interval of Vogt. Image from Zech and Hoeg, 2008.
Classification and external resources
Specialty	ophthalmology
ICD-10	H18.4
ICD-9-CM	371.41
OMIM	107800
DiseasesDB	17120
MeSH	D001112
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Arcus senilis (or arcus senilis corneae) is a white, grey, 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 is also called arcus adiposus, arcus juvenilis (when it occurs in younger individuals), arcus lipoides corneae or arcus cornealis; sometimes a gerontoxon.

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.

It can be a sign of disturbance in lipid metabolism, an indicator of conditions such as hypercholesterolemia, hyperlipoproteinemia or hyperlipidemia.

Unilateral arcus is a sign of decreased blood flow to the unaffected eye, due to carotid artery disease or ocular hypotony.

People over the age of 60 may present with a ring-shaped, grayish-white deposit of phospholipid and cholesterol near the peripheral edge of the cornea.

Younger people with the same abnormality at the edge of the cornea would be termed arcus juvenilis.

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Wikipedia