Abstract
Abstract: :
Purpose:This study sought to develop a reliable approach to quantify the in vitro wettability of soft contact lens materials and to report the wettability obtained with a variety of combinations of hydrogel polymers and commercially available care regimes. Methods:Axisymmetric Drop Shape Analysis-Profile (ADSA-P) was employed to measure the dynamic surface tension of four care regimes (AOSept, Complete Comfort PLUS, ReNu MultiPlus, OptiFree Express) and a control fluid (saline), and a new approach based on an image-capture technique was developed to measure the contact angle of the four regimes and the control fluid on five hydrogel contact lens materials (Focus Night&Day, PureVision, Optima 38, Acuvue, Proclear). This data was used to determine the surface free energy of the contact lens materials, using the equation of state approach. Results:Analysis of the results demonstrated that significant differences exist between the wetting angles of the lens materials and that the wetting angles obtained were significantly influenced by the care regimen which the material was exposed to. Wetting angles (θ) ranged from a high of 77 (PureVision with AOSept) to a low of 9 (Acuvue with OptiFree Express). The surface free energy values (in mJ/m2) of the lens materials from the lowest to the highest were PureVision (36), Focus Night&Day (45), Optima (52), Proclear (53) and Acuvue (54). General trends were clearly visible, in which the lowest wettability (highest θ) was obtained by materials exposed to non surfactant-containing regimes (saline and AOSept) and that silicone-containing materials (Focus Night&Day and PureVision) exhibited higher wetting angles than conventional hydrogel materials. Conclusion:These results indicate that currently available contact lens polymers exhibit a variety of in vitro wetting angles and that their in vitro wettability is significantly influenced by the composition of the care regime that they are exposed to.
Keywords: 367 contact lens