A patient presented with diminished vision and neuropsychiatric manifestations and with hepatic dysfunction.  His eyes on general examination and slit lamp examination appeared as shown in the Figure below.  What investigation you will do next?
Ref. API Textbook of Medicine. Pg. 870
 
Image represents “Kayser-Fleischer” ring -  KF ring is golden brown ring due to deposition of copper in Descement’s membrane of cornea.
 
Wilson’s Disease:

Rare autosomal recessive disease.
Characterized by abnormal copper metabolism

Sternlieb's criteria:

Presence of KF rings
Decreased serum ceruloplasmin (copper containing enzyme / ferroxidase) levels
Measuring hepatic copper levels in liver biopsy
24-Hr urine copper excretion

● Kayser Fleischer ring:

Excess circulating copper deposits in descemet’s membrane.
Usually golden brown located in peripheral cornea, beginning at schwalbe’s line upto 5 mm into cornea.
Detected via Gonioscopy in earlier stage & seen by naked eyes in advanced stage.
Serum ceruloplasmin level
24 hr Urine copper level
MRI brain
Haplotyping