Crystalline keratopathy due to kappa chains in a monoclonal gammopathy

The following case shows corneal crystal formation in a patient in whom thee systemic work-up led to the diagnosis of a monoclonal gammopathy with increased monoclonal immunoglobulin G (IgG). We present the corneal signs and subsequent haematological investigations undertaken to establish this important association. Systemic work-up of a patient with corneal deposits showed a monoclonal gammopathy with increased monoclonal immunoglobulin (IgG-type kappa). Corneal crystals, a rare, but significant, clinical finding, may be the initial presentation in a patient with monoclonal gammopathy.