Clinical and in vivo confocal microscopy findings in mgus - a case report

Purpose The purpose of this study was to describe a case of paraproteinemic keratopathy (PPK) in a patient with monoclonal gammopathy of undetermined significance (MGUS) Methods A 56 years old man was assessed using a slit lamp and in vivo confocal microscopy (IVCM) with Heidelberg HRT Rostock II. Results The patient showed bilateral diffuse, symmetric, non-polychromatic, punctiform crystals in all layers of the cornea. The remaining part of the ophthalmic clinical assessment was normal. Esthesiometry was normal in all quadrants. Anterior segment OCT confirmed diffused hyperreflectivity of the epithelium and corneal stroma. IVCM was then executed, showing polymorphic (granular, needle-like, stellate) hyperreflective crystals in all layers of corneal epithelium and anterior stroma, subbasal plexus nerves beading, cytoplasmatic hyperreflectivity of the keratocytes of the posterior stroma without any endothelial involvement After considering the age, health status, and ocular signs the primary entities to be investigated were adult benign cystinosis and paraproteinemic disorder. All the diagnostic tests were negative except for a monoclonal component IgG/k of 1.37 d/dl. A hematological examination was then performed with the resulting diagnosis of MGUS. In this paper, we analyzed 11 articles about IVCM in PPK in MGUS and other paraproteinemias highlighting IVCM features compatible with our findings allowing us to generalize a first diagnostic IVCM pattern for PPK. Conclusions In this case report we suggest the IVCM diagnostic patterns that may be used to identify PPK without corneal biopsy.