Plasma Treatment of Gas Permeable Contact Lenses

The last several years an exciting new technology for rigid gas permeable contact lenses has become available. Plasma coating treatment can be applied to most gas permeable contact lens materials (fluorosilicone acrylate rigid gas permeable (RGP) contact lenses). We usually refer to this as a coating in our Eye Clinic but some Eye Doctors believe it is strictly a cleaning process of the lens surface. Advanced Surface Technology, Inc. manufactures the system used in the contact lens industry to apply a plasma treatment. Plasma is a gas that has become partially ionized and is a unique form of matter with properties different from solids, liquids, or gasses. Plasma treatment processes vary, but most improve the ability of the treated surface to stay wet (hydrophilic). AST describes the PJ plasma treatment as a system to treat and clean the surface of various material including metals, ceramics, glass, and silicon. Plasma treating is excellent at removing organic contamination and often used to improve the bonding of subsequent coatings. Plasma treatments are used on some soft contact lenses (silicone hydrogel lenses) to improve wetting and make them more deposit resistant. These processes make definite alternations on the surface of the contact lens surfaces that are permanent. It is still not clear how a plasma treatment effects the surface of a gas permeable contact lens. There is no dispute that the lens surface is extremely clean and wets very well when first worn. There is some evidence that the surface properties of the contact lens material is altered by plasma treatment that results in increased wetting and comfort on an ongoing basis. My experience has been there is a definite surface alteration that results in an increase in eye comfort of 15-20 percent or more that lasts for 1-2 years. There is some controversy whether some solutions can damage this effect. We advise staying with what the manufacturers recommend and avoiding any harsh chemicals or abrasive cleaners. At this time, I view plasma treatments as coatings and believe any polishing of the lens destroys the surface benefits. I think plasma treatments are a tremendous advance in comfort technology and use them on every gas permeable lens we prescribe. Lens drying is probably the number one cause of lens discomfort and intolerance today and this is a welcome improvement, especially for contact lens wearers with dry eyes or living in dry climates like Fort Collins. Plasma treatments of gas permeable and soft contact lenses are at a very early stage of development and we can expect to see many improvements over time as the surface alterations are better understood and targeted on an individualized basis for maximum contact lens eye comfort, and lenses that are extremely deposit resistant and less prone to eye infections and allergic eye reactions.