Corneal crystalline deposits in multiple myeloma. A case report.

A 70-year-old man with a seronegative rheumatoid arthritis showed some peculiar lamellar crystalline deposits mainly at the Descement/endothelial level in both eyes. Serum protein analysis revealed a monoclonal gammopathy with increased amounts of IgG and K-light chains along with traces of the latter in the urine. Corneal biopsy was not available, but electron microscopy of the conjunctival specimen demonstrated crystalline deposits within the endoplasmic reticulum of plasma cells lying within the connective tissue. This material is supposed to be of protein nature. It seems reasonable that the conjunctival deposits are identical to those seen in the cornea by slit-lamp examination, and it is also suggested that they represents paraprotein aggregates. After treatment with melphalan (Alkeran) and prednisone systemically, the corneal deposits decreased over a period of 9 months with corresponding improvement of the visual acuity.