title: Role of silicon contamination on calcification of hydrophilic acrylic intraocular lenses.
abstract: OBJECTIVE
  To verify the presence of the element silicon on hydrophilic acrylic intraocular lenses (IOLs) explanted because of calcification.
  
  
  METHODS
  Interventional case series with clinicopathological correlation.
  
  
  METHODS
  Twenty explanted IOLs with surface deposits (MemoryLens), and 20 with deposits mostly within their optic substance (SC60B-OUV and Aqua-Sense; 10 each) were used. After gross, microscopic, and histochemical analyses to confirm the presence of deposits, the lenses underwent scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS) for elemental composition, on the external surface of MemoryLens IOLs, and on the surface and internal substance of SC60B-OUV and Aqua-Sense IOLs. The weight percentage of the element silicon was obtained at the level of deposits, and at adjacent deposit-free areas in all lenses.
  
  
  RESULTS
  Scanning electron microscopy (SEM) coupled with EDS confirmed that the composition of the deposits was calcium/phosphate in all cases. The element silicon was found in all 40 lenses, on all areas analyzed. The silicon weight percentage was higher at the level of the deposits. The presence of aluminum on five MemoryLens IOLs, and in most of the SC60B-OUV and Aqua-Sense lenses might be related to scattering from the aluminum mounting stubs used for surface analyses.
  
  
  CONCLUSIONS
  Silicone compounds have been implicated in the calcification of another hydrophilic acrylic design (Hydroview). They may also have a role in the calcification of other hydrophilic acrylic IOLs. Further investigation on the relationship between the presence of the element silicon and the silicone compounds found on calcified hydrophilic acrylic lenses is necessary.
authors.affiliation: John A. Moran Eye Center, University of Utah, 50 North Medical Drive, Salt Lake City, UT 84132, USA. liliana.werner@hsc.utah.edu
authors.forename: Liliana
authors.initials: L
authors.lastname: Werner
authors.forename: Brian
authors.initials: B
authors.lastname: Hunter
authors.forename: Scott
authors.initials: S
authors.lastname: Stevens
authors.forename: Jesse J L
authors.initials: JJ
authors.lastname: Chew
authors.forename: Nick
authors.initials: N
authors.lastname: Mamalis
mesh_terms: D000180:Acrylic Resins; D002114:Calcinosis / Q000209:etiology*; D002130:Calcium Phosphates / Q000032:analysis; D020878:Device Removal; D004577:Electron Probe Microanalysis; D019544:Equipment Failure Analysis; D006801:Humans; D007910:Lenses, Intraocular; D008855:Microscopy, Electron, Scanning; D011475:Prosthesis Failure; D012825:Silicon / Q000032:analysis*
chemical_list: D000180:Acrylic Resins; D002130:Calcium Phosphates; C020243:calcium phosphate; D012825:Silicon