Contact Lens Spectrum
Issue link: https://clssupplements.epubxp.com/i/740958
c l s p e c t r u m . c o m C O N T A C T L E N S S P E C T R U M S P E C I A L E D I T I O N 2 0 1 6 11 CONT ACT LENS DESIGN & MA TERIALS G R E G O RY J. N I XO N, O D, FA AO Dr. Nixon is the associate dean for Clinical Services and professor of clinical optometry at The Ohio State University College of Optometry. He is also in a group private practice in Westerville, Ohio. You can reach him at gnixon@optometry.osu.edu. NOVEL WETTING AGENTS MAXIMIZE MOISTURE RETENTION C ontact lens comfort has become a dominant focus of the contact lens industry in the last decade. With lens discomfort believed to be a main contributor to contact lens dropout, manufacturers have developed advances in lens materials and surface technology in an attempt to maintain the current market of contact lens wearers. These unique advancements have not only contributed to maintaining the contact lens market, but they have also grown the num- ber of teens and adults wearing contact lenses to an all-time high, accord- ing to a 2015 Gallup poll. The poll also found that 63% of contact lens wearers report being very satisfied with their lenses, which is an increase compared with the previous 2 years. Challenges to Contemporary Wearers Today's contact lens wearers battle significant challenges to comfortable lens wear. People of all ages spend a significant amount of time view- ing digital devices every day. This has created an epidemic of reduced blink rates due to extended periods of time eyes are concentrated on a screen. The increased exposure of the ocular surface and the contact lens surface create challenges to maintaining hydration and wettabil- ity throughout the day, resulting in reduced comfortable wearing times. Addressing the SiHy Challenge Because silicone is a naturally hydrophobic material, some silicone hydrogel (SiHy) materials can have surface non-wetting that can lead to symptoms of blur and discomfort. To allow for surface wettability, SiHy lenses need to incorporate some degree of chemical alteration to al- low for adequate compatibility with the ocular surface. The Bausch + Lomb Ultra lens addresses this challenge by sur- rounding the silicone-based lens infrastructure with polyvinylpyrrol- teraction between the cornea and contact lens. The lens surface also contains Poloxamer 407, which cre- ates a dehydration barrier at the lens surface to provide enhanced moisture retention throughout the day. Also, the neutrally charged lens provides surface integrity that can provide a stable lens performance. Use Material Innovation to Your Advantage Contact lens wearers demand high performance from their lenses. They desire a comfortable lens with crisp optics that provides good eye health and good comfort throughout the entire day. The innovative material science that incorporates maximal PVP concentrations into both SiHy and hydrogel lenses provides unique opportunities for you to meet your patients' needs. With enhanced wet- tability and moisture retention, you can deliver the performance that your patients desire. CLS For references, please visit www. clspectrum.com/references and click on document #SE2016. idone (PVP), a naturally hydrophilic substance. More importantly, the lens is able to maintain its mois- ture level effectively throughout a typical wear cycle of 16 hours. In addition, the Bausch + Lomb Ultra lens utilizes a unique combination of both long- and short-chain silicone polymers. This results in excellent oxygen transmissibility (Dk of 114), but also a low modulus of 70. A Daily Disposable Option The Biotrue Oneday lens (Bausch + Lomb) is a single-use hydrogel that also takes advantage of a substantial PVP concentration to maintain good wettability. In a hydrogel lens, the water-loving nature of PVP allows the lens to obtain a 78% water concentration, the same level as the cornea. This biocompatibility provides stable in- T o d a y' s c o n tac t le n s w e a r e r s b at t l e s i g n i f i ca n t ch a l l e nge s t o c o m fo r ta b le le n s w e a r . U F P. 0 2 8 7 . U S A . 1 6