Senile arcus 老年環

英文名稱：Senile arcus
中文名稱：老人弓, 角膜脂弓, 角膜弓, 邊緣弓, 脂肪弓, 角膜邊脂肪浸潤
名詞解釋：又稱老年環，若見於40歲以下者，則多伴有高脂血症，以家族性高膽固醇血症為多見。

• Arcus senilis (or Arcus senilis corneae. Latin: senile bow) is a type of corneal arcus, a peripheral corneal opacity.



• It is a whitish discoloration of the peripheral cornea - a cloudy complete or partial arc, highly visible over the iris. I



• t is caused by the deposition of phospholipid and cholesterol granules in the corneal stroma (or substantia propria) and usually occurs bilaterally and symmetrically. It is most often found in the elderly, hence the name. It can be a sign of disturbance in lipid metabolism, an indicator of conditions such as hypercholesterolemia, hyperlipoproteinemia or hyperlipidemia.



• A unilateral arcus is a sign of carotid artery disease or ocular hypotony.



• In younger individuals the condition is called Arcus juvenilis.



• a Sign of Possible Alcoholism (ref: Volume 4 Issue 1, Pages 104 - 106, 2008)



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