Hydrogen Peroxide Pride
contact lens management
Hydrogen Peroxide Pride
Hydrogen peroxide-based solution boasts delayed neutralization process.
ROBERT CHU, O.D. FT. WORTH, TEXAS
Because multipurpose solutions (MPS) are an effective form of disinfection and facilitate lens cleaning, as they do not require a cup or the physical addition of a neutralizing agent, several O.D.s and contact-lens wearers alike have flocked to these products instead of hydrogen-peroxide-based solutions for years.
With the recent recalls of MPS due to bacteria infiltration, however, I believe the eyecare industry will soon experience a shift from MPS back to hydrogen-peroxide based solutions. This is because despite the efficacy of MPS, research has shown that a hydrogen-peroxide-based solution is the most efficacious in eradicating microorganisms, including Acanthamoeba.1 This is where Ultra Care Disinfecting Solution, from Advanced Medical Optics (AMO), comes in.
UltraCare is a preservative-free disinfecting, neutralizing chemical lens-care solution and storage system for daily- and extended-wear soft (hydrophilic) contact lenses. It contains 3% hydrogen peroxide, has a hypotonic nature and a pH of 4.00, enabling it to penetrate the lens' hydrophilic material. This penetration provides a thorough cleaning (it removes protein, lipid build-up, trapped debris and penetrates microbial biofilms), as it expands the lens matrix and oxidizes microbes.
The key to UltraCare's success is tablets that come with the solution and delay the neutralization process. The patient adds time-release tablets to the UltraCare cup that neutralize the hydrogen peroxide at the beginning of the disinfection cycle, so the contact lens and any opposing organisms are initially exposed to full-strength peroxide. (Prolonged soaking in full-strength peroxide has been shown to achieve maximal disinfection.1-4) When the neutralization reaction is complete, these tablets color the UltraCare solution pink.
Although studies have revealed that contact-lens exposure to undiluted peroxide for 10 minutes eliminates most bacteria, you can best achieve antifungal efficacy by increasing exposure time. UltraCare delays the neutralization process for roughly 20 minutes, providing a longer exposure of the organisms to full-strength peroxide.
||ANTIMICROBIALS: Hydrogen peroxide 3%|
FORMULATION: Hydrogen peroxide 3% (stabilized with sodium stannate, sodium nitrate, and buffered with phosphates) and purified water
NEUTRALIZING TABLETS: Catalyase, hydroxypropyl methylcellulose, cyanocobalamine
CLEANING AGENT: Cleaning action provided by undiluted hydrogen peroxide 3%
DEMULCENT: Hydroxypropyl methylcelluose.
I also prescribe UltraCare to those daily- and extended-wear soft (hydrophilic) contact-lens wearers who have hypersensitive eyes and/or dry eye, as this preservative-free formula precludes the exacerbation of these symptoms. I've found that peroxide systems are beneficial for any ocular surface-challenged patients, including those taking long-term preserved drugs, such intraocular pressure (IOP)-lowering medications. OM
Dr. Chu would like to thank Jason Hassett, a second-year student at the Southern College of Optometry, for his assistance with this column. Jason is an intern at Dr. Chu's practice.
References furnished upon request.
DR. CHU MANAGES CHU EYE ASSOCIATES AND IS A MEMBER OF THE TEXAS OPTOMETRIC ASSOCIATION (TOA). E-MAIL HIM AT DRROBERT@EYEWORKS GROUP.COM.
Optometric Management, Issue: September 2007