title: Deposit buildup on prosthetic eye material (in vitro) and its effect on surface wettability.
abstract: BACKGROUND
  The aim of this in-vitro study was to investigate the effect of different polishing standards on prosthetic eye material (poly(methyl methacrylate) [PMMA]) on surface wettability and the rate of protein and lipid buildup.
  
  
  METHODS
  Sample disks (12 mm diameter × 1 mm thickness) of PMMA were polished to three different standards of surface finish: low, normal, and optical quality contact lens standard. The sample disks were incubated in a protein-rich artificial tear solution (ATS) for the following periods of time: 1 second, 30 minutes, 1 hour, 4 hours, 24 hours, and 14 days. Surface wettability was measured with a goniometer before and after protein deposits were removed. One-way analysis of variance and paired-samples t-test were used for the statistical analysis.
  
  
  RESULTS
  Between 13.64 and 62.88 μg of protein adhered to the sample disks immediately upon immersion in ATS. Sample disks with the highest polish attracted less protein deposits. The sample disks polished to optical quality contact lens standard were more wettable than those less highly polished, and wettability significantly decreased following removal of protein deposits. The addition of lipids to protein-only ATS made no difference to the amount of protein deposited on the sample disks for any of the standards of surface polish tested.
  
  
  CONCLUSIONS
  The findings are consistent with the results of the in-vivo investigation reported previously by the authors. Our view that the minimum standard of polish for prosthetic eyes should be optical quality contact lens standard and that deposits on PMMA prosthetic eyes improve the lubricating properties of the socket fluids has been reinforced by the results of this study.
authors: Department of Optometry and Vision Science, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand;
authors: Keith Raymond
authors: KR
authors: Pine
authors: Brian
authors: B
authors: Sloan
authors: Kyuyeon Ivy
authors: KI
authors: Han
authors: Simon
authors: S
authors: Swift
authors: Robert John
authors: RJ
authors: Jacobs
keywords: PMMA; protein deposits; surface polish