Surface roughness and refractive index changes in contact lens induced by lens care systems

摘要

Purpose: The aim of this study was to analyze the influence of differentlens care systems in surface roughness and refractive index (RI) of contactlenses (CL). This information provides us with a better understanding ofhow care solutions affect CL materials.Methods: Several CL and three commercially available and appropriatelens care solutions were used (two polyhexamethylene biguanide and onehydrogen peroxide care systems). Lenses were immersed in the lens caresystems, and then measurements with CLR 12-70 digital automatedrefractometer and atomic force microscopy analysis on Tapping modewere recorded. The measurements were performed before and after thelenses were immersed in each care solution.Results: Significant changes were observed on the CL materials whenexposed to lens care systems. All the materials changed, to a greater orlesser extent, their roughness and RI, after being immersed in the differentsolutions. The water content varied between 0% (Nelfilcon A in ReNuMultiplus, Senofilcon A in AOSEPT Plus, and Methafilcon A in SolocareAqua) and 4.1% (Hilafilcon B in Solocare Aqua) The higher change inroughness was obtained with ReNu Multiplus in the lens Comfilcon A (withan increase of 27.2 nm) and Senofilcon A (with an increase of 16.7 nm).Conclusion: This study suggests that lens care systems play an importantrole in surface roughness and RI of CL.