Purpose: To report an ultrastructurally distinct form of paraprotein crystalline keratopathy.
Methods: Three corneas submitted from a single patient including one native cornea from each eye and a failed corneal graft from the right eye. Light microscopy, immunohistochemistry, immunofluorescence, and transmission electron microscopic examination were performed.
Results: The transmission electron microscopy showed “immunotactoid” extracellular microtubular deposits measuring >30 nm in diameter with a central lucent core.
Conclusions: Immunotactoid keratopathy is a distinct type of paraprotein crystalline keratopathy associated with a monocolonal immunoglobulin G kappa light chain (IgGk) protein. Larger case series are needed to determine the clinical significance of this entity.