Arcus senilis
From Wikipedia
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.
Alternative names
It is also called arcus adiposus, arcus
juvenilis (when it occurs in younger individuals), arcus
lipoides corneae or arcus cornealis; sometimes a gerontoxon.
Causes
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.[2]
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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