Reader and Industry Forum

Diligent Disinfection in 49 Steps

By Graeme Young, MPhil, PhD, FCOptom, DCLP, FAAO

It is often said that most patients are noncompliant in their use of contact lens care systems. The truth is, though, that all patients are noncompliant. How could this be otherwise, given the punishing daily routine that we ask patients to follow?

Weighty Expectations

Soft contact lens care systems once resembled kids' chemistry sets, but manufacturers rightly compliment themselves on having simplified the process to a one-bottle, multipurpose experience. However, count the number of steps that we ask patients to remember, and you may be embarrassed at the over-ambitious weight of expectation (Table 1). The question is not whether any of these steps in the daily routine are overlooked, but which steps are overlooked?

Arguably, each of the 49 steps is critical and poses a unique risk when missed or done incorrectly, but some are more critical compared to others. The existence of “no-rub” multipurpose solutions implies that steps 35 and 44 can be occasionally overlooked. Unfortunately, many patients take this as an instruction rather than an option, with potentially dangerous consequences (Rosenthal et al, 2003, 2004). Because the “no-rub” option assumes that the rest of the routine is carefully followed, missing steps 21, 36, and 45, for instance, can push a system to the brink (Rosenthal et al, 2003, 2004; Hall and Jones, 2010; Szczotka-Flynn et al, 2010). Overlooking step 26 increases the risk of microbial infection, while missing steps 29 and 48 risks Acanthamoeba infection (Anger and Lally, 2008).

In recent years, the precarious nature of effective disinfection, coupled with human nature and its short-comings, has resulted in cases of serious complications. Thus, care products should not only disinfect, but do so under adverse conditions. Rosenthal et al (2003, 2004) showed that noncompliance with various steps can reduce a system's disinfection efficacy. The bactericidal activity of one PHMB-based solution, for instance, was undetectable after three days of lens storage. Efficacy with some products was inadequate when dirt was introduced to the case. Interestingly, eliminating the rinse step was more problematic compared to eliminating the rub step because the rinse step was 10 times more effective at removing microbes.

Recommendations for Improved Lens Care

The challenge for conscientious practitioners is to determine where in the routine each patient is likely to compromise. Do they economize by topping off? How good is their personal hygiene? Good clinical antennae are helpful, and asking to see lens cases can provide additional clues. Look upon it as a personal challenge to uncover the flaws in your patients' routine.

Part of the skill set of a good clinician is the ability to persuade patients to do the right thing. There are numerous strategies that you can employ. A guiding principle, though, is that patients must understand why they should be following a given routine and what the consequences might be if they abbreviate. Clinical support staff are invaluable in patient education, and it is important, therefore, to ensure that they are properly trained. Easily understood written instructions can help; with modern technology, it is relatively simple to produce personalized patient literature. Table 2 lists some key guidelines often missing from manufacturers' instructions. More enterprising practitioners even produce instructional videos for transmitting to patients' cell phones.

The onus lies not only with patients and practitioners but also with industry, and it is surely time to mandate the supply of new lens cases with every bottle of lens care solution. This has been the standard practice in Europe for more than a decade as a response to our own home-grown Acanthamoeba epidemic back in the '90s. It seems unfair that U.S. contact lens wearers should be denied a safety provision offered to users in other countries.

A further, often overlooked potential for problems is the bathroom environment itself and airborne contaminants. Aerosol fecal spray from toilets can increase the microbial load (Gerba et al, 1975). Even with case lids in place, contamination to the outside of the lens case can be transferred to fingers and passed on to the lens during application. Cosmetic sprays can also find their way into the lens care solution and initiate toxic reactions when brought into contact with the cornea. A final step in the daily routine should be to place the case in a safe location, out of harm's way.

Always Room to Improve

The science of contact lens disinfection is increasingly better understood, but there is still progress to be made in the art of persuading patients to care for their lenses in a safe and more effective manner. CLS

To obtain references for this article, please visit http://www.clspectrum.com/references.asp and click on document #195.