H18.043 Kayser-Fleischer ring, bilateral

Name of the Condition

• Kayser-Fleischer Ring, Bilateral
• ICD Code: H18.043

Summary

Kayser-Fleischer ring, bilateral, is a brownish or greenish ring of copper deposition in the cornea of both eyes, typically located at the limbus (the border between the cornea and sclera). This finding is a key clinical sign of Wilson disease, a genetic disorder affecting copper metabolism. The ring may be visible to the naked eye in advanced cases but is often detected via slit-lamp examination.

Causes

Kayser-Fleischer ring results from abnormal copper accumulation in the body due to impaired biliary excretion, a hallmark of Wilson disease. Copper deposits in the Descemet membrane of the cornea, forming the characteristic ring. The underlying cause is mutations in the ATP7B gene, which disrupts copper transport and elimination.

Risk Factors

• Genetic predisposition (family history of Wilson disease)
• Age (typically appears in late childhood or early adulthood)
• Untreated or poorly managed Wilson disease
• Lack of copper metabolism screening in at-risk individuals

Symptoms

• Often asymptomatic initially; may be detected during routine eye exams
• In advanced cases, potential visual disturbances (e.g., glare, blurred vision)
• Associated systemic symptoms of Wilson disease (e.g., liver dysfunction, neurological issues)

Diagnosis

Diagnosis involves slit-lamp examination to visualize the corneal deposits. Additional tests may include serum ceruloplasmin levels, 24-hour urinary copper excretion, and genetic testing for ATP7B mutations to confirm Wilson disease. Imaging or liver biopsy may be used to assess systemic involvement.

Treatment Options

Treatment focuses on reducing copper levels and managing Wilson disease. This may include chelating agents (e.g., penicillamine, trientine) to remove excess copper, zinc supplements to block absorption, and dietary modifications to limit copper intake. Regular monitoring of copper levels and organ function is essential.

Prognosis and Follow-Up

With early diagnosis and treatment, prognosis is favorable, and symptoms may improve. Untreated Wilson disease can lead to severe liver damage, neurological decline, or death. Lifelong follow-up is required to monitor copper levels, treatment efficacy, and organ function.

Complications

• Progressive liver cirrhosis or failure
• Neurological deterioration (e.g., tremors, speech difficulties)
• Kidney damage
• Hemolytic anemia
• Psychiatric symptoms

Lifestyle & Prevention

• Adhere to prescribed treatments and regular monitoring.
• Follow a low-copper diet (avoid shellfish, organ meats, nuts, and chocolate).
• Avoid copper-containing supplements or cookware.
• Genetic counseling for at-risk family members.

When to Seek Professional Help

Seek immediate medical attention if you experience unexplained fatigue, jaundice, neurological changes, or visual disturbances, especially if you have a family history of Wilson disease.

Tips for Medical Coders

Document the bilateral nature of the Kayser-Fleischer ring and its association with Wilson disease, if confirmed. Ensure clinical documentation supports the diagnosis and specifies the eye involvement (bilateral) to justify code H18.043. Note any related systemic findings or confirmatory tests for accurate coding.