Article Date: 2/1/2010

For Current Care Systems, Rub and Rinse is the Best Option
point TOPIC: Rub Versus No Rub

For Current Care Systems, Rub and Rinse is the Best Option

BY TIMOTHY T. MCMAHON, OD, FAAO

In this Point/Counterpoint debate I have been asked to discuss the position that rubbing and rinsing prior to disinfection is the superior and therefore preferred means to care for contact lenses (other than daily disposable lenses that are meant to be disposed of after each day of use). I believe that I have the easier of the two positions to defend.

My colleague, who will have the task of convincing you that no-rub systems are safe and effective, will have convenience on his side. Indeed, the notion of simply removing contact lenses, dropping them in a case, and splashing a little multipurpose solution after them is awfully tempting. Knowing how frequently patients do not follow our instructions regarding the care and handling of their contact lenses, an option that requires them to simply find their case and plop their lenses in it seems the right thing to do to protect them from themselves.

The Rub

Paternal as this argument may appear, there is an important problem with this perspective: it requires that the lens care solution used must be effective in killing anything that can bind to the lens, be transferred to the eye, and harm patients.

Unfortunately, no current lens care systems meet that standard. The existing ANSI standards adopted by the U.S. Food and Drug Administration (FDA) Ophthalmic Devices Branch require a series of tests on a panel of bacteria and fungi. The organisms originate from specific laboratory lines that have been replicated for years, some species going back 40 years or more. Additionally, Acanthamoeba, a recognized human pathogen, is not included. Moreover, for some organisms, namely the fungi, the FDA requires only a single log unit reduction in the number of viable bugs after a disinfection cycle in the “stand alone test.” The organisms being used by the manufacturers, which were developed to provide a level playing field for all competitors, are not as virulent as wild types—which are the bugs in the environment that infect your patients.

Schoff and colleagues (2008) demonstrated that none of the multipurpose solutions on the U.S. market are effective against Acanthamoeba cysts. Even peroxide systems had limited effectiveness in killing cysts. A number of investigators have demonstrated limited killing efficacy against fungal organisms by the multipurpose solutions as well. How many fungi or Acanthamoeba trophozoites does it take to infect a human cornea? At present no one knows. Two important solution-related infectious keratitis outbreaks have occurred in recent years, and the number of cases of Acanthamoeba keratitis continues to rise in some parts of the country. It seems imprudent to recommend no-rub systems in the face of this evidence.

Efficacy Speaks for Itself

What we do know is that rubbing and rinsing is effective in removing infectious agents from contact lenses. In fact, this part of the lens care regimen is more effective in reducing the load of infection-capable organisms than the stand alone disinfection part of a regimen is. The FDA recently held two meetings to address the matter of contact lens disinfection standards, and it will most likely insist upon tougher disinfection standards going forward. For now the Ophthalmic Devices Panel has recommended that the rub-and-rinse part of the disinfection process be reinstated.

Practitioners and the government have asked the solution industry to make safe and effective products that can go on the eye. The manufacturers have complied admirably. However, we go too far when we drop the rub-and-rinse part of the process for the sake of convenience. CLS

For references, please visit www.clspectrum.com/references.asp and click on document #171.


Dr. McMahon has been a faculty member at the University of Illinois at Chicago in the Department of Ophthalmology and Visual Sciences for 29 years and currently holds the rank of professor of Ophthalmology. He is a Diplomate in the Section on Cornea and Contact Lenses of the American Academy of Optometry. He is also a consultant or advisor to B+L.

counterpoint

Questioning the Clinical Benefit of Rubbing Contact Lenses

BY ARTHUR B. EPSTEIN, OD, FAAO

Few issues have aroused as much passion as the rub versus no rub controversy. The arguments both pro and con seem simple enough, yet they are surprisingly complex and multifaceted. Put simply should contact lens patients rub their lenses or should they not? Does rubbing have real clinical benefit?

Disposable lenses changed the way patients and practitioners viewed contact lenses. Up until then, contact lenses were costly and seen by most patients as medical devices requiring professional management. Disposability made contact lenses appear to patients as inexpensive, readily available commodity items.

Because disposable lenses are replaced frequently and cost little to replace, patients perceive them as requiring less care. Practitioners continued to recommend rubbing, but patients didn't seem to listen. Surveys confirmed that only 50 percent of patients actually followed lens care instructions. This patient-practitioner disconnect spurred development of the first no-rub solution by Alcon. Soon every major solution maker had introduced a no-rub product.

Does Rubbing Really Help?

After more than 20 years of prescribing frequent replacement lenses, clinical experience suggests that rubbing lenses has become superfluous. Yes, heavy depositors, especially those using conventional and extended-replacement modalities, benefit from rubbing. Perversely, non-compliant over-wearers who would benefit most are the least likely to follow care instructions.

While some studies have shown reductions in deposits and microbial loads when lenses were rubbed, other studies have demonstrated no benefit or equally dramatic cleanliness differences when different no-rub products were compared. Clinically, rubbing compared to not rubbing lenses makes little difference for most patients.

Patient behavior confirms this reality. I mentioned previously that only 50 percent of patients rubbed their lenses before the advent of no-rub solutions. Surveys taken after the introduction of no-rub products showed little change in patient behavior. Even at the height of the Fusarium outbreak when contact lens experts deluged the popular media with admonitions to rub, half of all patients rubbed and half didn't.

Proponents of rubbing point to the recent outbreaks and a general increase in rates of lens-related microbial keratitis (MK) as reasons to require rub instructions on product labeling. However, exhaustive epidemiologic analysis of both Fusarium and Acanthamoeba outbreaks by the U.S. CDC found no relationship between rubbing, patient hygiene and infection risk. Patients who rubbed lenses were just as likely to develop infections as those who did not.

Our clinical experience bears this out. How often do seriously noncompliant patients develop MK? Patients have old and filthy cases and regularly over wear their lenses, some even use saline and yet infections even in this group remain exceedingly rare.

Rubbing May be Harmful

Admonishing a happy asymptomatic patient to rub when it is unlikely that he will follow those directions can weaken clinical authority and even damage the doctor-patient relationship. Telling all patients to rub may make you feel better, but it will be of little benefit for most patients.

I believe that requiring rub instructions on all lens care products only legitimizes rub dogma while disincentivizing industry from creating products that would provide an effective safety net for the half of our patients who just won't rub. This may make the FDA feel better, but it will do little to protect patients. CLS

For references, please visit www.clspectrum.com/references.asp and click on document #171.


Dr. Epstein is a well known clinician, author, and lecturer. A senior partner of North Shore Contact Lens & Vision Consultants, Long Island, NY, he is also attending staff at North Shore University Hospital, NYU School of Medicine. Dr. Epstein has received speaking honoraria, research grants or served as a consultant for Alcon Labs, Ciba Vision, CooperVision, and Vistakon.



Contact Lens Spectrum, Issue: February 2010