MONOCLONAL CORNEAL GAMMOPATHY - TOPOGRAPHIC CONSIDERATIONS

Desposition of immunoglobulins in the cornea occasionally occurs in be nign and malignant lymphoproliferative conditions. A 52-year-old woman with recently discovered monoclonal gammopathy of undetermined signif icance (MGUS) was referred to our hospital, Slit-lamp and ultrasound b iomicroscopy revealed bilateral deposits within all corneal layers. Th e precipitates were organized in a circle, leaving a perilimbal zone a nd the axial cornea clear. Light microscopy of a biopsy disclosed conf luent subepithelial deposits and defects in Bowman's layer, Immunopero xidase reaction was positive only for IgG and IgG-kappa. Transmission electron microscopy confirmed the presence of extracellular rectangula r and arcuate immunoglobulin crystalloids with a IO-nm periodicity but a non-crystalline defraction pattern. A review of the literature show ed that the circumferential pattern of immunoglobulin deposition is as sociated with short-term visual symptoms and good visual acuity. The p resent report supports a hypothesis of immunoglobulin lin deposition v ia the limbal arcade and contradicts the ''tear theory.''