title: Corneal crystals: a precursor to cancer.
abstract: OBJECTIVE
  Corneal crystalline deposits are a sign of a limited number of conditions that can often be differentiated based on the appearance and pattern of the deposits. Although, there are limited treatment options available to reduce the appearance or effects of corneal crystals, it is important to identify the correct etiology of these deposits. There are several associated systemic conditions, some of which are life threatening, for which treatments are available.
  
  
  METHODS
  A 51-year-old black male presented to the clinic with the complaint of "glare at night due to crystals on [the] cornea." Slitlamp findings revealed diffuse subepithelial and anterior stromal crystals across both corneas.
  
  
  RESULTS
  The patient had a medical history of renal insufficiency and arthralgia. Through systemic testing, the patient was found to have monoclonal gammopathy of undetermined significance (MGUS), and subsequent follow-up of this patient revealed a conversion of MGUS to multiple myeloma.
  
  
  CONCLUSIONS
  Corneal crystals can appear diffusely through the cornea secondary to corneal dystrophies, gammopathies, cystinosis, or other rare systemic conditions. In this case report, these crystals are secondary to MGUS, which progressed to multiple myeloma. These crystals consist of immunoglobulin, primarily IgG, and excessive kappa light chains. It is important to obtain laboratory tests and make appropriate referrals to determine whether corneal crystal deposits are associated with a serious systemic disease or merely a corneal dystrophy.
authors.affiliation: FAAO VA Medical Center, Hampton, VA, USA.
authors.forename: Janel L
authors.initials: JL
authors.lastname: Chou
authors.forename: Makesha L
authors.initials: ML
authors.lastname: Sink
mesh_terms: D003315:Cornea / Q000378:metabolism* / Q000473:pathology*; D003319:Corneal Stroma / Q000378:metabolism / Q000473:pathology; D003460:Crystallization; D018450:Disease Progression; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry / Q000378:metabolism; D007145:Immunoglobulin kappa-Chains / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology*; D010265:Paraproteinemias / Q000378:metabolism* / Q000473:pathology*; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology*
chemical_list: D007074:Immunoglobulin G; D007145:Immunoglobulin kappa-Chains