One Lens Care Solution is Enough
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One Lens Care Solution is Enough
BY MICHAEL MAYERS, OD, FAAO
I recently attended a practice management seminar in Atlanta. Conversing with different practitioners during breaks at this seminar, I learned that some practitioners are instructing patients to alternate between two contact lens care solutions. Most were recommending that patients use a multipurpose solution (MPS) for five nights and a hydrogen peroxide-based system for the other two nights. When I asked the practitioners why they were recommending two different care systems versus one, the majority responded that they felt this recommendation provided the necessary cleaning and disinfection for each patient—especially with silicone hydrogel lenses, which sometimes can deposit lipids more frequently.
In this article I would like to examine the effects of recommending two lens care systems and how patients perceive this recommendation.
Contact Lens Care Compliance
But before we examine each lens care system, let me discuss contact lens care compliance. Dr. Ralph Stone presented a poster at the British Contact Lens Association annual conference in May 2007. His poster demonstrated the results from a survey regarding handwashing before handling lenses. His survey reported that 35 percent of patients do not wash their hands at all before handling lenses, 42 percent wash hands but leave them wet during handling, and 34 percent handle lenses throughout the day without proper disinfection.
Moreover, a study by Dumbleton et al (2009) showed that patients did not replace their lenses as directed by the manufacturers' recommended replacement frequency. The most noncompliant group was two-week replacement lens wearers. More than 52 percent of subjects who were wearing two-week replacement silicone hydrogels wore their lenses for longer than prescribed.
These two studies illustrate that no matter how much we educate our patients on lens care compliance, a percentage of them are going to be noncompliant and do what they think is best. Patients who are noncompliant with their lens care could put themselves at risk for microbial keratitis and other complications.
Hydrogen Peroxide Systems
Hydrogen peroxide solutions have been in existence since the early 1970s. These earlier systems were traditionally called two-step systems, which meant that the lenses soaked in hydrogen peroxide for four to six hours and then a catalyst was added to neutralize the solution. Most systems used today are considered one-step systems and are designed to be more convenient to use. One-step systems quickly start the neutralization process by a catalyst and complete this process in less than 60 minutes. Re-growth of microorganisms such as Acanthamoeba is a concern because the solution has no disinfecting properties once it is neutralized.
Harris et al (1989) looked at using over-the-counter (OTC) hydrogen peroxide versus the manufacturer's supplied hydrogen peroxide that comes with the neutralization mechanism (tablets or disc). The study found that the pH of the generic OTC hydrogen peroxide for one-step systems was statistically different and lower after the neutralization cycle (pH 4) versus the manufacturer's recommended hydrogen peroxide (pH 6.5 after neutralization). Patients who do not neutralize the solution before lens application will also obviously cause a chemical keratitis to their eye.
MPSs are complex formulations consisting of chelating agents for deposit removal, polymers for wetting the lens surface, and antimicrobial agents for disinfection. They were first introduced in the early 1990s. MPSs usually require a four- to six-hour soak for full disinfection of microorganisms. MPSs may also help rid the lens of surface deposits. Pucker and Nichols (2009) showed that rinsing a contact lens as directed by the package insert increases the protein removal. Lin et al (2008) demonstrated that a polyquad-based system removed 20 percent more proteins from silicone hydrogel surfaces versus other MPSs. Researchers at Waterloo performed biochemical lipid analysis on silicone hydrogel surfaces and demonstrated that polyquad-based systems remove 37 percent more lipids from a silicone hydrogel surface compared to the hydrogen peroxide-based system tested.
Another aspect of MPSs is the wetting agents they incorporate. Contact lens dryness is the number-one reason why patients discontinue lens wear. These polymers may help keep lenses moist and maintain end-of-day comfort. In addition, research has shown that MPSs can maintain their disinfection efficacy out to 30 days.
Send the Right Message
So is it advisable to tell patients to use a hydrogen peroxide-based system for two nights a week while using an MPS on the other nights? And is it advisable to give patients multiple starter kits when dispensing lenses? I believe neither is acceptable. What kind of message are we conveying when we give patients two lens care solutions to use? They might just think that each one alone is not good enough and perhaps mix the two solutions together. Or they may think that all lens care solutions are the same and then switch to a store brand or, even worse, store their lenses in sterile saline solution.
I believe we have enough non-compliance and patient confusion regarding lens care, contact lens case replacement, and solutions. You should make a strong recommendation—or “pro”scription—for a single care system based on each patient's wearing needs, eye physiology, and solution/material combination. CLS
To obtain references for this article, please visit http://www.clspectrum.com/references.asp and click on document #173.
Dr. Mayers is in private practice in Powell, Ohio, focusing on managing dry eye disease and fitting contact lenses with an emphasis on specialty contact lens fits. He has served as a National Board Examiner and has lectured nationally on various topics. He also conducts clinical research studies in the field of contact lenses and contact lens solutions. He is a consultant or advisor to Alcon.
Contact Lens Spectrum, Issue: April 2010