(KF rings) are dark rings that appear to encircle the iris
of the eye
. They are due to copper
deposition as a result of particular liver diseases. They are named after Dr Bernhard Kayser and Dr Bruno Fleischer, the German
doctors who first described them in 1902 and 1903. Initially thought to be due to the accumulation of silver, they were first demonstrated to contain copper in 1934.
As Kayser-Fleischer rings do not cause any symptoms, it is common for them to be identified during investigations for other medical conditions. In certain situations, they are actively sought; in that case, the early stages may be detected by slit lamp
examination before they become visible to the naked eye.
The rings, which consist of copper
deposits where the cornea
meets the sclera
, in Descemet's membrane
, first appear as a crescent at the top of the cornea. Eventually, a second crescent forms below, at 6 o'clock, and ultimately completely encircles the cornea.
Kayser-Fleischer rings are a sign of Wilson's disease
, which involves abnormal copper handling by the liver resulting in copper accumulation in the body and is characterised by abnormalities of the basal ganglia
of the brain
, liver cirrhosis
, involuntary movements, muscle rigidity
, psychiatric disturbances, dystonia
. The combination of neurological symptoms, a low blood ceruloplasmin
level and KF rings is diagnostic of Wilson's disease.
Other causes of KF rings are cholestasis (obstruction of the bile ducts), primary biliary cirrhosis and "cryptogenic" cirrhosis (cirrhosis in which no cause can be identified).