Saturday, August 1, 2009

FDA discussed no-rub contact lens solutions

From "Off-the-cuff" by Art Epstein OD: In mid-May, the FDA sent a letter to manufacturers who have marketing clearance for no-rub multipurpose contact lens solutions. The letter expressed apparent FDA concerns with “no-rub” solutions, and was ostensibly based on “the discussion and recommendation of the Ophthalmic Devices Panel Advisory Committee”. I attended that advisory panel meeting and what the FDA reports and what I observed were considerably different.

The letter explains that the FDA Center for Devices and Radiological Health (CDRH) worked with “the Centers for Disease Control and Prevention (CDC) twice in the past two years concerning outbreaks of rare corneal pathogens associated with use of specific “no-rub” contact lens multipurpose solutions”. However, as you will read in the next paragraph, despite the apparently intentional emphasis, the products' “no-rub” approval had nothing to do with the outbreaks—at least not according to the US CDC.

As a clinician, I found the presentation by Jennifer Rabke Verani, MD, MPH, who represented the CDC, the most intriguing part of the panel meeting. Dr. Verani reported that patient hygiene, including rubbing and rinsing or even hand washing, played no role in either the Fusarium or Acanthamoeba outbreaks. The CDC concluded that both outbreaks were due to insufficient anti-microbial efficacy and were not associated with the lack of rubbing and rinsing by patients. These important conclusions appear to have been ignored by the FDA.

According to the FDA, the Advisory Committee concluded “that there is improvement in lens care when using a “rub-and-rinse” regimen as compared to a “rinse alone” regimen”. This is because “rub-and-rinse” regimens help prevent microbial adhesion to the contact lens, help prevent formation of biofilms, and generally reduce the microbial load on the lens and the lens case”. I would agree that rubbing likely results in cleaner lenses, but the FDA's broad generalizations are neither totally accurate nor scientifically sound. Despite the long held belief that rubbing reduces infection risk, we still lack the clinical or scientific evidence to prove it.

Panel member Dr. Tim McMahon, perhaps recognizing the potential safety net provided by an advanced no-rub formulation, recommended supporting no-rub labeling, provided products could meet the same stringent antimicrobial requirements necessary for rub products. To my recollection, the panel agreed with Tim.

The direction the FDA appears too be taking is worrisome. We don't fully know what constitutes an infectious load on a contact lens or what co-factors predispose a cornea to infection. Likewise, disregarding statistically valid conclusions from two in-depth epidemiological investigations is inexplicable. If the FDA intends to promulgate new rules to help safeguard contact lens wearers, at the very least, new regulations should be based on science rather than on dogma or regulatory agenda.

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