title: Corneal Densitometry for Quantification of Corneal Deposits in Monoclonal Gammopathies.
abstract: OBJECTIVE
  To assess the capability of Scheimpflug-based densitometry of the cornea to quantify light chain deposits in patients with active monoclonal gammopathies.
  
  
  METHODS
  This is a case-control study in which data from a leading tertiary university center in myeloma care were analyzed. Ten eyes of 5 patients with monoclonal gammopathy and 26 eyes of 13 healthy controls undergoing clinical evaluation and Scheimpflug-based measurements were included in the study. The main outcome measures were densitometry data of the 4 corneal layers-anterior layer (AL), central layer (CL), posterior layer, and total layer (TL)-in 4 different annuli (central annular zone 0-2 mm, intermediate annular zone 2-6 mm, peripheral annular zone 6-10 mm, and total annular zone 0-12 mm).
  
  
  RESULTS
  In 8 eyes of 4 patients with IgG-based gammopathy, corneal light backscatter was highest in the AL and decreased with increasing corneal depth. The peripheral annular zone showed a higher densitometry value compared with the corneal center. Compared with healthy controls, the AL (P < 0.001), the CL (P < 0.001), and the TL (P < 0.001) had significantly higher corneal light backscatter in patients with gammopathy in the total and the peripheral annular zones. In one patient with predominantly IgA-based disease, corneal light backscatter was not elevated.
  
  
  CONCLUSIONS
  Scheimpflug-based densitometry of the cornea is able to quantify opacification by immunoglobulin G light chain deposits in monoclonal gammopathies. This noninvasive technique can complement presently used in vivo confocal microscopy and corneal photography to objectivize corneal changes. Densitometry might allow monitoring of corneal immunoglobulin deposits in follow-up examinations.
authors.affiliation: Departments of *Ophthalmology; and †Internal Medicine I, Hematology, and Oncology, University Hospital of Cologne, Cologne, Germany.
authors.forename: Philip
authors.initials: P
authors.lastname: Enders
authors.forename: Udo
authors.initials: U
authors.lastname: Holtick
authors.forename: Friederike
authors.initials: F
authors.lastname: Schaub
authors.forename: Armin
authors.initials: A
authors.lastname: Tuchscherer
authors.forename: Manuel M
authors.initials: MM
authors.lastname: Hermann
authors.forename: Christoph
authors.initials: C
authors.lastname: Scheid
authors.forename: Claus
authors.initials: C
authors.lastname: Cursiefen
authors.forename: Björn O
authors.initials: BO
authors.lastname: Bachmann
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003315:Cornea / Q000473:pathology*; D003318:Corneal Opacity / Q000175:diagnosis* / Q000503:physiopathology; D019781:Corneal Topography; D003720:Densitometry; D005260:Female; D019466:Glare; D064368:Healthy Volunteers; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008027:Light; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D010265:Paraproteinemias / Q000175:diagnosis* / Q000503:physiopathology; D010781:Photography / Q000379:methods; D012542:Scattering, Radiation; D014792:Visual Acuity / Q000502:physiology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G