Contact Lens Care & Compliance
Hydrogen Peroxide Contact Lens Disinfection, Part 2
By Susan J. Gromacki, OD, MS, FAAO
In my May 2012 column, I discussed the mechanism of action and neutralization of ophthalmic hydrogen peroxide (H2O2). This month I will present additional information on H2O2 systems.
What's in the “Brown Bottle”?
Contact lens care system hydrogen peroxide is different from that found in “brown bottles” at a pharmacy or retail outlet. First of all, it is specifically cleared by the U.S. Food and Drug Administration (FDA) for ophthalmic use. The “brown bottle” peroxide is not micro-filtered, purified, or sterile. It may also contain heavy metals or stabilizers that are not suitable for ophthalmic use. Additionally, “brown bottle” peroxides may vary in percentage of hydrogen peroxide from bottle to bottle, do not provide a method for neutralization, and are hypotonic, which may cause lenses to bind to the cornea upon application. Furthermore, “brown bottle” H2O2 is not buffered and can have pH as low as 3.5, quite different from the pH of the tears (7.4 to 7.6).
Lastly, ophthalmic hydrogen peroxide may contain surfactants, which aid in the cleaning and comfort of contact lenses.
All of the currently available hydrogen peroxide-based systems in the United States are defined as “one-step”: disinfection and neutralization occur simultaneously. In addition to AOSept (Alcon), the original one-step system, there are three distinct formulations (other labels do exist for some solutions, including the OcuSoft Lens Care System [Ocu-Soft], launched in April).
Clear Care (Alcon) combines a cleaner (Pluronic 17R4) and disinfectant (H2O2) in one bottle. With a five-second rinse, it is FDA-approved for no-rub. It has a six-hour neutralization period and is approved for seven days of storage. It is the only H2O2 system indicated by the FDA for silicone hydrogel lenses. Lastly, Clear Care is approved for use with GP lenses, with which a digital rubbing step is required.
Oxysept UltraCare (Abbott Medical Optics [AMO]) is the hydrogen peroxide component of a three-bottle system. AMO requires cleaning with a separately purchased daily cleaner and then rinsing with saline prior to placing lenses in the basket lens holder. An advantage to this system is the presence of a wetting agent (hydroxypropyl methylcellulose) in the neutralization tablet. It is recommended that lenses be placed directly onto the eyes in the morning so as not to rinse off the lubricant. The catalase tablet also includes cyanocobalamin (vitamin B12), which creates a pink hue just before total neutralization (six hours) to indicate that the tablet was placed into the solution. Maximum storage time is seven days. The package insert contains a contraindication with Illusions (tefilcon) lenses (Alcon), as it may cause lens damage.
Sauflon One-Step (Sauflon) contains a built-in cleaner and has no-rub approval with a five-second per side (20 seconds total) rinse prior to disinfection. It is the only one-bottle H2O2 system with a rewetting agent and is “Eyecare Professional Specific:” it is not available through retailers. This may aid in monitoring patient compliance with lens care. Neutralization with the catalytic disc takes six hours; storage time should not exceed 24 hours before re-disinfecting.
Peroxide System Case Care
For all of these systems, turning the lens case upside down can neutralize any remaining H2O2 on the inside of the cap. After removing the lenses, inverting the lens case with fresh, un-neutralized peroxide will disinfect the inside cap. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #202.
|Dr. Gromacki is a diplomate in the American Academy of Optometry's Section on Cornea, Contact Lenses and Refractive Technologies and practices in Lutherville, Md.|