Contact Lens Care & Compliance
An Upgraded Peroxide Lens Care Solution Enters the Market
BY MICHAEL A. WARD, MMSC, FAAO
Clear Care Plus with HydraGlyde (Alcon) is a new formulation and an addition to our contact lens disinfection armamentarium. It is a one-step, 3% hydrogen peroxide (H2O2)-based cleaning and disinfecting system approved for all soft and GP lenses that keeps lenses cleaner and provides long-lasting moisture, according to the company. Clear Care Plus with HydraGlyde represents a product line extension and is not meant to replace the original Clear Care product. Alcon says the new care solution is the same product as AOSept Plus with HydraGlyde that was launched in Europe last fall (Redman, 2015).
Clear Care Plus Chemistry
The preservative-free, aqueous Clear Care Plus contains hydrogen peroxide 3%, phosphonic acid as a stabilizer, sodium chloride 0.79% to create an isotonic saline solution, a phosphate buffer to control pH, Pluronic 17R4 as a surfactant cleaning agent, and HydraGlyde Moisture Matrix (also found in Alcon’s Opti-Free multipurpose solution [MPS] products). HydraGlyde is a proprietary, surface-active block copolymer of polyoxyethylene and polyoxybutylene (EOBO-21) that is especially suited to increase the surface wettability of silicone hydrogel soft lenses, according to the company. The addition of EOBO-21 has no impact on the solution’s antimicrobial activity, which is equivalent to Clear Care (Gabriel et al, 2015).
More on Peroxide Disinfectants
H2O2-based lens disinfecting products offer antimicrobial efficacy without the use of preservatives. They contain 3% hydrogen peroxide as the active ingredient in a microfiltered, stabilized, and buffered aqueous solution.
Peroxides are effective against a wide variety of organisms: bacteria, fungi (including spores and yeasts), viruses, and some protozoa. Hydrogen peroxide destroys pathogens by oxidation, creating the fleeting free radical superoxide, which is toxic to DNA. Peroxides also denature proteins, thus damaging necessary microbial cell structures. Unlike most disinfecting agents, hydrogen peroxide is unaffected by organic matter or salts. Hydrogen peroxide penetrates microbial biofilms, which preservative-based MPS products cannot (Gabriel et al, 2015; Ward, 2003).
The hydrogen peroxide in these systems must be neutralized prior to lens wear, as unneutralized peroxide is toxic to the ocular surface. A concern with any hydrogen peroxide-based disinfection product is the potential for contamination if lenses are stored in previously neutralized solution. Although hydrogen peroxide systems have high antimicrobial efficacies at full strength, all peroxide disinfecting systems become unpreserved aqueous bathing solutions capable of supporting microbial growth once neutralized.
I have found that peroxide disinfecting systems outperform MPS products in keeping lenses clean and comfortable, and they are safe and effective if used daily. Peroxide systems are approved for up to seven days of storage. However, if lenses have been soaking in the neutralized solution for longer than one day, I advise patients to repeat the disinfecting/neutralization procedure prior to wear. Patients should also make sure to keep the inside of the lens case cap clean, as little or no disinfection occurs on these surfaces. A new lens storage/neutralization case is provided with each new purchase. It is necessary to use the new case to ensure consistent neutralization and safety. Patients should follow the manufacturer’s instructions provided with each system (Ward, 2003). CLS
For references, please visit www.clspectrum.com/references and click on document #237.
Mr. Ward is an instructor in ophthalmology at Emory University School of Medicine and director, Emory Contact Lens Service. You can reach him at email@example.com.