Issue link: https://optometricmanagementsupplements.epubxp.com/i/587112
S P E C I A L E D I T I O N 2 0 1 5 • O P T O M E T R I C M A N A G E M E N T . C O M 15 What's more, the changing environ- ments that people experience daily, as well as the intense demands we make on our eyes, all may afect opti- cal performance and comfort. A contact lens changes the ocular surface environment dramatically. On the eye, a contact lens "splits" the tear flm, trapping the vital mucin layer behind the lens, dramat- ically reducing the volume of aque- ous, and disrupting the lipid layer. 7 A thinner pre-lens tear flm layer increases evaporation and shortens tear flm break-up time, which can impact vision. 8 Ideally, a contact lens would mim- ic the tear flm. To do that efectively requires a lens with tear-like proper- ties that can interact with and sup- port not just its water component but the full range of tear flm constitu- ents: mucins, aqueous and lipids. TEAR-INFUSED DESIGN To meet this challenge, Johnson & Johnson Vision Care, Inc., has introduced ACUVUE OASYS Brand Contact Lenses 1-Day with HydraLuxe Technology with a tear- infused design. Tese new lenses are comprised of an enhanced network of tear- like molecules plus highly breathable hydrated silicone that integrates with the patient's own tear flm each day (Figure 2), and leverages all the bene- fts of daily disposability as well. Tis network of tear-like molecules is uni- form throughout the lens, not simply a coating, and works consistently all day as opposed to having to be blink released. Because the natural tear flm is a complex system, the lenses are designed to work with the key tear flm components (not just water) to lubricate and moisturize the lens and support the tear flm throughout the day. (See "Tear-Infused Design," page 16.) HOW TO MIMIC MUCINS — AND WHY At the heart of HydraLuxe Technology is an enhanced mois- ture network with increased covalent bonding designed to further reduce the adhesiveness of the lens to better mimic the eye's own mucins. Distrib- uted evenly throughout the enhanced moisture network is high molecular weight polyvinyl pyrrolidone (PVP), a remarkable wetting agent with a long history of use in ophthalmics and biomaterials. 9 In HydraLuxe Technology, PVP with a specifcally formulated chain length and molecular weight is added to a reactive monomer mix to create a matrix that closely mimics the properties of mucin. Like naturally occurring tear flm mucins, the PVP in the lenses contains sites that interact with all key tear components. Figure 2: ACUVUE OASYS Brand Contact Lenses 1-Day with HydraLuxe Technology (the middle, lighter section) are comprised of an enhanced network of tear-like molecules plus highly breathable hydrated silicone that integrates with the patient's own tear flm each day. Figure 1: High molecular weight mucins are bound to the cornea on one end but have hydrophilic tails that extend into and hold the aqueous to the cell surface. Because cell membranes are largely hydrophobic, without these mucins, tears would run off the corneal surface. At the same time, the mucins act as a disad- hesive so the corneal epithelium doesn't stick to the tarsal conjunctiva. Contact Lens FE ATURE INSPIRED BY THE SCIENCE OF TE ARS