Showing papers by "Lyndon Jones published in 2001"

The ex vivo wettability of soft contact lenses

Abstract: Purpose. To investigate the ex vivo wettability of Etafilcon A contact lenses over an eight hour period of wear and observe the influence of surfactant pre-treatment. Methods. Etafilcon A hydrogel lenses, comprising poly[2-hydroxyethyl methacrylate-co-methacrylic acid] and 58% water, were soaked for 12 hours in either 0.9% saline (control) or a 1% aqueous solution of poloxamine 1107 (treated). The advancing and receding contact angles were subsequently determined ex vivo after various periods of wear in six adapted contact lens wearers using a single-blind, randomised protocol. Contact angles were measured with a dynamic contact angle tensiometer, using the Wilhelmy plate technique. Patient comfort scores were recorded and the static surface tensions of the probe fluids assessed. Results. Control lenses exhibited no change in wetting angles over time, indicating a lack of surface modification by components within the tear film. Treated lenses exhibited a significantly reduced advancing angle (p < 0.001...