Contact Lens Care & Compliance
New Technology Coming to Peroxide-Based Lens Care
BY MICHAEL A. WARD, MMSC, FAAO
The U.S. Food and Drug Administration (FDA) has cleared the Intelli-Case from NovaBay Pharmaceuticals. Intelli-Case is an electronic contact lens disinfecting/storage case that monitors the neutralization of hydrogen peroxide as it cleans and disinfects contact lenses (www.medgadget.com/2015/06/novabays-intelli-case-makes-cleaning-contact-lenses-hydrogen-peroxide-cinch-video.html). It is part of the NovaClear hydrogen peroxide contact lens disinfection system.
The Intelli-Case has a “traffic light” type LED display on the case lid that signals “Unsafe (red), Busy (yellow), or Ready (green)” (Figure 1). According to the company, the red light flashes if the platinum disc is not working, the peroxide concentration is too low (e.g., use of saline or multipurpose solution, topping-off), non-ophthalmic grade peroxide is used, or if lens storage has exceeded the seven-day maximum limit. A yellow LED blinks during the lens disinfection cycle. A green LED blinks when the lens disinfection cycle has ended—and for the next seven days—to indicate that the lenses are now safe to wear.
Figure 1. The Intelli-Case uses electronics to monitor the peroxide neutralization process
and to indicate whether lenses are safe to wear.
COURTESY OF NOVABAY PHARMACEUTICALS
The case deactivates after 60 to 65 cycles or after approximately two months, after which it needs to be replaced. The NovaClear system is currently FDA-cleared but not yet marketed in the United States.
More on Peroxide Disinfectants
Hydrogen peroxide-based contact lens disinfection systems have been around since the mid-1980s. Hydrogen peroxide products offer strong antimicrobial efficacy without the use of preservatives.
Microfiltered, stabilized, and buffered 3% hydrogen peroxide is the active ingredient in peroxide-based systems. They are effective against a wide variety of organisms, including 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 denature proteins, thus damaging necessary microbial cell structures (Ward, 2006).
The hydrogen peroxide in these systems must be neutralized prior to contact lens wear, as unneutralized hydrogen peroxide is toxic to the ocular surface. The platinum disc used in most hydrogen peroxide systems catalyzes the hydrogen peroxide into water and oxygen. Most contact lens wearers who use peroxide-based systems discover (usually only once) that attempting to wear a contact lens rinsed with the unneutralized peroxide solution is a painful experience.
An additional concern with any hydrogen peroxide disinfection product is the potential for contamination of contact lenses stored in previously neutralized peroxide solution. Although hydrogen peroxide systems have high antimicrobial efficacies at full strength, once neutralized they become unpreserved aqueous bathing solutions capable of supporting microbial growth. CLS
To obtain references for this article, please visit http://www.clspectrum.com/references and click on document #241.
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.