Abstract
Purpose :
A new silicone hydrogel (SiHy) material, lehfilcon A (TOTAL30®) with surface modification of a 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, was recently developed. This study was designed to evaluate the in vitro surface biological interactions as well as their impact on tear film stability on the surface of lehfilcon A and other reusable SiHy materials.
Methods :
The surface structures of lehfilcon A, comfilcon A, senofilcon A, senofilcon C, and samfilcon A contact lenses were imaged using Atomic Force Microscopy (AFM). After fouling in an artificial tear lipid solution, the distributions of fluorescently labeled non-polar lipids on the entire lenses as well as the cross-sections of these SiHy materials were visualized and quantified in three-dimensional (3D) via confocal laser scanning microscopy (CLSM). The in vitro tear film stability on the fouled lens surface was further assessed using a modified multifunctional topographer method.
Results :
Lehfilcon A contact lenses exhibited distinctive surface features and topographies resulting from its densely packed MPC polymer units, which was not seen on other reusable SiHy materials. Fluorescent intensity measurements of 3D CLSM images (Figure 1) showed that lipid deposition on the lens surface was significantly less for lehfilcon A compared to the other reusable SiHy materials (p<0.05 for all). Furthermore, lehfilcon A demonstrated a significantly longer surface moisture break up time than other tested contact lenses in the in vitro topography videos (19 s vs. <5 s, p<0.05 for all).
Conclusions :
The hydrophilic nature of the MPC polymer layer provided an antifouling surface feature for lehfilcon A contact lenses, which delivered greater in vitro tear film stability than other reusable SiHy contact lenses. These exceptional characteristics may help achieve outstanding on-eye performance for this new SiHy contact lens.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.