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Comparative study of silicone‐hydrogel contact lenses surfaces before and after wear using atomic force microscopy

2007; Wiley; Volume: 85B; Issue: 2 Linguagem: Inglês

10.1002/jbm.b.30954

1552-4981

Madalena Lira, Lívia Santos, Joana Azeredo, Eva Yebra‐Pimentel, M. Elisabete C.D. Real Oliveira,

Laser Applications in Dentistry and Medicine

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