Abstract

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignancy preceding multiple myeloma and related disorders. In MGUS ocular involvement is a rare occurrence although several cases have been reported of crystalline deposits in the corneal stroma. The pattern of the corneal opacities is very varied, and the appearance can mimic various degenerative changes and inherited diseases, including corneal dystrophies and cystinosis. Iridescent crystalline deposits throughout the stroma are the most common sign, but nummular sub-epithelial lesions, stromal lattice lines and granular deposits, diffuse stromal opacity, and a peripheral corneal ring have also been described. We report a suspected case of MGUS presenting with crystalline deposits over the Descemet's membrane which is an infrequent manifestation of the occult systemic disorder. Due to the risk of progression to a malignant state in MGUS, early diagnosis and monitoring is imperative.