Choosing the Right Solution
Choosing the Right Solution
Consider disinfection, wetting, cleaning and how overall performance matches the patient's lifestyle.
Dr. Potter: What key factors do you consider in choosing a contact lens care solution?
Dr. Mayers: The four key things I look for are disinfection, wetting, cleaning and overall performance—how it performs for each patient. Today, I'm mostly choosing a care solution for silicone hydrogels, which have nearly doubled in use since 2005 to comprise 60% or 70% of the market (Nichols, 2010).
On the whole, patients wearing silicone hydrogels experience less limbal hyperemia, which they like from a cosmetic standpoint, and we see less corneal edema (Dumbleton, 2006; Sweeney, 2003). But we may be seeing other unique complications on the rise (Carnt, 2009).
So with those four key considerations in mind, I tend to start by looking at care solutions that have been tested with them and have demonstrated good performance clinically.
Dr. Potter: You're considering disinfection, wetting, cleaning and performance for the individual. How do you determine that fourth characteristic?
Dr. Mayers: I have a discussion with patients about their lifestyles and what they want to do with their lenses. For example, maybe the patient works a third shift, wearing lenses at night and sometimes sleeping in them. I select the lens material, and then I start looking at bio-compatible care solutions to minimize redness, end-of-day dryness and enhance biocompatibility and reduce the potential for corneal staining. From there, I can prescribe a care solution that offers the best chance for success.
PRESCRIPTIONS, NOT GRAB BAGS
Dr. Mayers: Some practitioners go to their trial lens counter or their contact lens care starter kits and give patients a grab bag of three or four care solutions to try. That's not the approach we want to take going forward. It gives patients the idea that all care solutions are the same, so they may as well pick whatever they want at the store.
Give one strong recommendation and explain why you don't want patients to deviate. When you explain that you chose it because of their lifestyle, that personal touch instills trust and confidence in you for their contact lens care, as well as their medical care.
Dr. Sindt: About a year-and-a-half ago, my institution went to a policy of no sampling of any products, including contact lens care solutions and medications. At first I thought it would be disastrous. I thought patients needed to leave my clinic with a sample of care solution, so they would have something to use that night and would know what to buy in the store. As it turns out, it has been absolutely fine.
I think some doctors think giving patients a bottle of care solution is a recommendation, but it's not—it's just a free sample.
We've now switched to a prescription basis. We have our care solutions in the database, and when I print out the contact lens prescription, I print a prescription for the care solution that I want them to use and the explanation of why I chose that product. I think that carries more weight than handing them a free sample.
Dr. Potter: I recently discovered the power of writing care solution prescriptions. Patients started calling the office when they lost their prescriptions. If I gave them coupons or samples, they wouldn't give a thought to losing them. But when they lose their prescription—and I'd already explained its importance—they want that information. It's clear that our recommendations are meaningful to patients (Figure 7).
Figure 7. Studies have shown that doctor recommendations play an important role in care solution selection.
Dr. Miller: I call that explanation “the review.” I take those last two or three minutes after I've finished my exam to review the record—tell them what's going on, why I've prescribed a medication, a specific lens or a care solution. Those few minutes are reserved for reviewing with patients. That's such a critical aspect of what we do.
PLANNING AROUND COMPLIANCE
Dr. Potter: Let's talk more about patients who are non-compliant. What do you want the care solution to provide if you're fairly certain a patient isn't going to comply with your recommendations?
Dr. Mayers: Well, most multipurpose care solutions are approved for 30 days of storage in the lens case with the lens material, while one-step hydrogen peroxide solutions are typically approved for 7 days (Christie, 1997).
Most one-step hydrogen peroxide-based solutions say, “Soak for 6 hours,” and they are approved for 7 days of storage time, but they maintain less than 10% hydrogen peroxide concentration after 60 minutes (Christie, 1997).
Research shows that a 3% hydrogen peroxide soak for 4 hours actively kills acanthamoeba cyst, but I think a lot of the hydrogen peroxide neutralizes fast, and generally you're not getting a full-strength disinfection (Hughes, 2001).
So, when we're talking about non-compliant patients and microbial loads and bioburdens, I choose a multi-purpose care solution that provides disinfection with long-term storage.
Dr. Potter: How about the differences between multi-purpose care solutions?
Dr. Mayers: In one study, Surevue† (Johnson & Johnson) lenses were soaked for 7 days in a Polyquad* and Aldox* disinfecting system and a PHMB-preserved system (Rosenthal, 2001 and 2006). They found that the Polyquad* and Aldox* disinfecting system maintained its disinfection efficacy against Pseudomonas and Staphylococcus aureus, while the disinfection efficacy of the PHMB solution dropped off substantially (Rosenthal, 2001 and 2006).
In another more recent study, Acuvue† 2 (Johnson & Johnson) lenses were soaked for a week in the same types of solutions (Rosenthal, 2001 and 2006). Fusarium disinfection with the solution containing Aldox* preservative was effective over 1 week, whereas after 48 hours, they saw a re-growth of fusarium with the PHMB-preserved solution.
Dr. Miller: This is a huge point to me—especially for our very non-compliant patients. What happens in that care solution over the course of a week when they don't change it?
Dr. Mayers: Yes, it's very important for practitioners to understand. We need to look at lenses' kinetics and dynamics. What's going on in the preservative uptake and release? Before corneal staining happens, what's going on in the case while a care solution soaks at night with the lens material? Care solutions are tested with microorganisms, but may not be tested with lenses if they pass stand-alone primary criterion.
A revised preservative uptake and release ISO standard was published in November 2010, the goal of which is to evaluate uptake and release kinetics of a care solution with lenses.
Dr. Sindt: We need to keep learning how contact lenses and care solutions interact with the cornea so that down the road, we can make contact lens wear even safer. We can't just focus on this idea of compliance being the key. CLS
*Registered trademark of Alcon
†Trademarks are the property of their respective owners.
Contact Lens Spectrum, Issue: March 2011