Presence of pseudo-Kayser-Fleischer rings in patients without Wilson disease: a prospective cohort study

Kayser-Fleischer (KF) rings are due to copper deposition in Descemet membrane of the cornea in Wilson disease. Pseudo-KF ring (PKF), seen in patients with high bilirubin, is often misinterpreted as KF rings. These are bilirubin deposits in posterior corneal stroma. The aim of the study was to prospectively evaluate the presence of KF and PKF rings in Wilson disease and non-Wilsonian liver disease with serum bilirubin >5 mg/dL.

All patients referred from the hepatology unit with serum bilirubin >5 mg/dL were assessed by slit-lamp examination (SLE) and anterior segment optical coherence tomography at baseline, 3 months, and 6 months for differences in corneal deposits between KF and PKF rings. All other clinical, laboratory, radiological, genetic, and tissue diagnoses by liver biopsy were done as required to confirm the cause of liver disease.

Among the 750 patients examined, corneal deposits were present in 13%, KF rings as granular deposits in 31.7%, and PKF as a posterior stromal hue in 68.3% of cases. PKF rings showed regression in 60%, disappearance in 36.6% at 3 months, and in 100% of cases at 6 months. KF ring showed regression in 10.7% and 8.3% until 6 months. Anterior segment optical coherence tomography identified KF ring as a hyperintense line on Descemet membrane in an additional 9.7% of patients compared with a scattered hyperintense hue in PKF rings.

The presence of PKF rings in patients with jaundice is not uncommon and should be differentiated from true KF rings. Serial monitoring is essential to look for resolution, and anterior segment optical coherence tomography may be additionally helpful.