(681c) Can You Believe Your Eyes? High Comfort Contact Lens Wear Around the Clock

Comfort agents are commonly used in eye drops to sequester and retain water within the ocular tear fluid, while enhancing other comfort contributing properties, such as tear viscosity, tear film stability, and lubrication. In addition, incorporating comfort agents into various ophthalmic devices, such as corrective contact lenses, significantly increases ocular comfort and biotolerance. A novel contact lens material was engineered for the controlled, simultaneous release of trehalose, a low molecular weight disaccharide, and 120 KDa hydroxypropyl methylcellulose (HPMC). Through molecular imprinting, a high degree of control over the release of both trehalose and HPMC was achieved, the first demonstration of simultaneous release of comfort agents from the same lens. Trehalose has been shown to provide high levels of comfort to the eye when delivered from eye drops, but this is the first demonstration of release from contact lenses. Release of trehalose was controlled to provide high levels of comfort during the first half of lens wear by sequestering high levels of water within the tear fluid to prevent dry eye discomfort. End of day discomfort is provided by the extended release of HPMC, which maintains lens lubrication, refreshes the lens surface, and prevents lens dehydration as well as lowers protein adhesion to the surface of the lens. By applying the principles of molecular imprinting to a silicone hydrogel contact lens, high level of control over the release of trehalose and HPMC was achieved. Increasing the molar ratio of acrylic acid to comfort agent (M/T) demonstrated independent control over the release of both HPMC and trehalose, extending the trehalose duration of release by approximately 5,000%. In addition, use of molecular imprinting improved loading, optical clarity, and physical properties of the lens. For the first time, incorporation of HPMC was shown to lower protein adhesion to the surface of the lens by up to 30%. By utilizing trehalose to provide high initial wear comfort and HPMC to ensure end of day lens comfort, it is hypothesized that the maximum level of lens wear comfort can be achieved. To demonstrate the high level of comfort provided by this lens, a novel rating system was developed based on previously undetermined relationships between comfort properties and the effect of different comfort agent species, comfort agent solution concetration, and comfort agent molecular weight.