KF ring is seen in –
**Core Concept**
The Kayser-Fleischer (KF) ring is a medical sign characterized by a copper deposit in the Descemet membrane of the cornea, often indicative of Wilson's disease, a genetic disorder leading to copper accumulation in the body.
**Why the Correct Answer is Right**
The KF ring forms due to the deposition of copper in the Descemet membrane, a thin layer of tissue in the cornea. This is a result of the impaired transport of copper in Wilson's disease, leading to its accumulation in the body and eventually in the cornea. The copper deposition in the Descemet membrane causes a brownish or golden ring to appear in the periphery of the cornea.
**Why Each Wrong Option is Incorrect**
**Option A:** The KF ring is not typically associated with hemochromatosis, a condition characterized by iron overload. While both conditions involve metal deposition, they are distinct and unrelated.
**Option B:** The KF ring is not seen in primary biliary cirrhosis, a liver disease characterized by immune-mediated destruction of bile ducts. Although liver disease can be associated with Wilson's disease, the KF ring is a specific indicator of copper accumulation.
**Option C:** The KF ring is not a characteristic finding in Alzheimer's disease, a neurodegenerative disorder characterized by cognitive decline and memory loss. While both conditions involve neurodegeneration, they are distinct and unrelated.
**Clinical Pearl / High-Yield Fact**
The Kayser-Fleischer ring is a specific and sensitive indicator of Wilson's disease, making it a crucial diagnostic clue in patients presenting with liver disease, neurological symptoms, or psychiatric symptoms.
**Correct Answer: D. Wilson's disease**