From Laboratory to Clinical Practice
Opti-Free PureMoist MPDS meets the needs of today's contact lens wearers.
By David Meadows, PhD
Eyecare practitioners are increasingly upgrading contact lens wearers from traditional to silicone hydrogel contact lenses, often because the latter supply higher oxygen levels to the cornea, reducing complications associated with corneal hypoxia. This results in special challenges for silicone hydrogel lens wearers as complete wetting of the lenses is necessary for full tear-film coverage, minimized tear film disruption and smooth tear recovery upon lid closure. Continued step-wise progress has improved our understanding of interactions between lenses and the ocular environment and our ability to optimize this dynamic relationship.
One approach to improve success with contact lenses is to create a lens care product that conditions the silicone hydrogel materials for a longer-lasting, more wettable surface, and decreases friction between the lens and eyelid. Through extensive use of laboratory methods by multiple teams of researchers, a new, specifically designed wetting agent, HydraGlyde Moisture Matrix was created. This agent is a proprietary multifunctional linear di-block copolymer composed of poly(oxyethylene)-poly(oxybutylene) (EOBO). Through overnight soaking, HydraGlyde embeds on and within the lens surface, thus masking the hydrophobic areas of the lens with hydrophilic sites. This improves lubrication and provides wettability for at least 16 hours.1,2 These effects have been verified through an array of sophisticated laboratory techniques, including contact angle measurements, lipophilic dye diffusion assessments, and several microscopic techniques used to investigate the surface properties of contact lenses at the nanometer level.
In addition to providing extended moisture, an ideal multipurpose disinfecting solution must maintain a high level of disinfection efficacy, provide excellent cleaning, and be stable for long-term storage. The foundation of a new contact lens disinfecting product is its antimicrobial activity against representative challenge organisms defined by FDA and ISO standards.
Opti-Free PureMoist MPDS contains the patented and proven Polyquad and Aldox dual disinfecting system, which has been used for more than 13 years by millions of successful contact lens wearers worldwide. Opti-Free PureMoist MPDS has been shown to meet the requirements for primary stand-alone disinfection efficacy and has been shown to have efficacy against selected clinically relevant microorganisms.3
The new formulation was introduced to contact lens wearers in the context of two large clinical trials involving more than 1,100 contact lens patients. Results confirmed that Opti-Free PureMoist MPDS is well tolerated by patients and offers advantages in terms of subjective assessments that are key to a positive lens-wearing experience.4-6
Opti-Free PureMoist MPDS also removes protein deposits, reduces lipid deposition and results in minimal corneal staining, which will be shown through data presented in this Special Edition of Contact Lens Spectrum. By soaking the lenses overnight in the solution, contact lens wearers experience comfort and moisture from insertion to removal.4-6 While beneficial to all lens wearers, Opti-Free PureMoist MPDS may provide special advantages for patients who experience dryness and end-of-day discomfort, the two primary factors that result in patients dropping out of contact lenses.6
This special issue of Contact Lens Spectrum includes a variety of articles that describe how Opti-Free PureMoist MPDS was developed, tested in the laboratory and evaluated clinically over many years. The solution was designed to meet the needs of both patients and eyecare professionals, and provides an advanced entry into the contact lens care marketplace. CLS
1. Davis J, Ketelson HA, Shows A, Meadows DL. A lens care solution designed for wetting silicone hydrogel materials. Poster presented during ARVO annual meeting; May 2010; Fort Lauderdale, Fla.
2. Huo Y, Perry SS, Rygalov A, Wang A, Ketelson HA, Meadows DL. Chemical and frictional analysis of silicone hydrogel contact lens surfaces. Poster presented during ARVO annual meeting; May 2010; Fort Lauderdale, Fla.
3. Kern JR, Kappell G, Callan M, McNamee L, McAnally C, Walters R Borazjani RN. Antimicrobial properties of a novel contact lens disinfecting solution, Opti-Free EverMoist. Poster presented during BCLA meeting; May 2011; Manchester, England.
4. Napier L, Garofalo R, Lemp J, Ketelson H, Lally J. Clinical evaluation of an investigational multi-purpose disinfecting solution. Poster presented during CLAO meeting; September 2010; Las Vegas.
5. Garofalo RJ, Napier LD, Lemp JM, Ketelson HA, Stein JM, Lally, JM. Clinical performance of a new multi-purpose disinfecting solution. Poster presented during BCLA meeting; May 2011; Manchester, England.
6. Data on file, Alcon Laboratories, Inc.
|Dr. Meadows is vice president of vision care development at Alcon, where he is responsible for new OTC products in the areas of contact lens care, dry eye and ocular vitamins. He has held several positions of increasing responsibility since joining Alcon Labs in 1994. His research interests include contact lens performance measurements, clinical intervention of dry eye, ocular surface disease and tear film biophysics.|