Lipid Deposition on Silicone Hydrogel Lenses, Part I: Quantification of Oleic Acid, Oleic Acid Methyl Ester, and Cholesterol

Abstract

To investigate the sorption of oleic acid, oleic acid methyl ester, and cholesterol on currently marketed silicone hydrogel contact lenses. Two liquid chromatography methods were developed and used to analyze lens extracts from continuous-wear and daily-wear modalities from asymptomatic silicone hydrogel contact lens wearers. Of the three probed compounds, cholesterol is the most prevalently sorbed, at levels ranging from below the limit of quantitation (<1.50 microg per lens) to approximately 37.0 microg per lens. Oleic acid and oleic acid methyl ester were found to exist at levels below the limit of quantitation (<1.50 microg per lens). In general, there appears to be no significant difference between the amounts of cholesterol sorbed on the continuous-wear PureVision and daily-wear PureVision lenses evaluated. The quantities of lipid sorbed to continuous-wear PureVision lenses are significantly different from those previously reported by other authors in a similarly conducted experiment. This difference suggests that any hypothesis of silicone hydrogel lenses based on these previous lipid data should be reconsidered.