Vanishing corneal epithelial crystals following thalidomide induced resolution of myeloma related paraproteinaemia

Investigations revealed a raised plasma viscosity (3.28 cp), an IgG-κ paraprotein (55.9 g/l), free immunoglobulin light chains in the urine (0.49 g/24 hours), a hypercellular bone marrow aspirate (70-80% plasma cells), and a single lytic bone lesion in the left iliac crest. Comment Corneal crystalline deposits may occur in cystinosis, multiple myeloma, and other monoclonal gammopathies, infective crystalline keratopathy, Schyder's central crystalline dystrophy, Bietti's marginal crystalline dystrophy, gout, chronic renal disease, lipid keratopathy, and chrysiasis. 1 Crystalline keratopathy occurs only rarely in association with multiple myeloma and monoclonal gammopathies. 2, 3 With the exception of Waldenstrom's macroglobulinaemia, the crystals are composed of IgG light chains (usually κ 3- 6 but occasionally λ 7 ).