Comparative study of silicone-hydrogel contact lenses surfaces before and after wear using atomic force microscopy
✍ Scribed by M. Lira; L. Santos; J. Azeredo; E. Yebra-Pimentel; M. Elisabete C. D. Real Oliveira
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 408 KB
- Volume
- 85B
- Category
- Article
- ISSN
- 1552-4973
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✦ Synopsis
Abstract
Purpose: The aim of this study was to analyze surface changes of three silicone‐hydrogel contact lenses after daily wear. The lenses used in this study were balafilcon A, lotrafilcon B (both surface‐treated), and galyfilcon A (non surface‐treated). Methods: To understand how and where proteins, lipids, and other contaminants change contact lenses, surface roughness was assessed through Atomic Force Microscopy Tapping Mode™. Roughness parameters were Mean Surface roughness (R~a~), Mean‐square‐roughness (R~q~), and Maximum roughness (R~max~). The surface topography of unworn and worn lenses was also mapped in great detail. Results: Contact lenses roughness parameters exhibited different values before and after wear and the surface appearance also changed. After wear, balafilcon A and galyfilcon A showed a significant increase on surface roughness parameters, being this increase more accentuated to galyfilcon A. In lotrafilcon B materials no significant changes were observed with wear. Conclusions: The present study suggests that surface treatment of silicone‐hydrogel contact lenses can play a role in the prevention of a significant increase in roughness, and contribute to the better clinical tolerance of these lenses. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008