An Eye on Contact Lens Solutions

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Eduoard H.R. Gluck / Bloomberg News / Landov

Three twin packs of Advanced Medical Optics' Complete MoisturePlus eye solution sit on a pharmacy shelf in New York, Tuesday, May, 29, 2007.

For contact lens wearers, the story has become a familiar one: a contact lens solution is yanked from the market amid reports of potentially debilitating disease. This time around, the product is Complete MoisturePlus, manufactured by Advanced Medical Optics (AMO), on news from the Centers for Disease Control and Prevention (CDC) that the multi-purpose solution is linked to a rare but serious eye infection that can severely corrode the cornea and even lead to blindness.

The recall is the latest in a string that has kept contact wearers wondering what solution is safe to use. Just a year ago, Bausch & Lomb was the company in the hot seat after the CDC released data on a different kind of eye infection that showed a disproportionate number of people suffering from the disease had been using the company's ReNu with MoistureLoc. The company issued a massive recall and discontinued the solution worldwide. Since then, there has been a handful of less-widespread recalls, set off by issues ranging from bacterial contamination in a Chinese plant to the detection of trace amounts of iron that could cause lens cleaner to lose its effectiveness.

The narrative of the Complete MoisturePlus recall, announced on May 25, closely echoes what happened last year with ReNu MoistureLoc, although the microbes involved were different. In each case, local clinicians first noticed an uptick in a rare eye condition and reported the spike to the CDC, which launched an investigation and subsequently found that many people with the disease reported using the same contact solution. The disease involved in last year's ReNu MoistureLoc recall was the fungal infection Fusarium keratitis. The disease associated with the Complete MoisturePlus recall is caused by Acanthamoeba, a water-borne parasite that occurs naturally but in the human eye can lead to serious infections of the cornea. The CDC interviewed 46 people who had the condition, called acanthamoeba keratitis, and found that 21 of them reported using Complete MoisturePlus — amounting to a risk seven times greater for people using the product than those who weren't. At this point, it isn't clear why that correlation exists. Or what lessons might be drawn from the similarity of this year's recall with last year's. "We're not prepared to make any generalizations at the moment," says CDC medical epidemiologist Dr. Sharon Roy, "but it does bring up questions about multi-purpose solutions."

One of those questions, says cornea specialist Dr. William Ehlers, is whether multi-purpose solutions, standard products for soft contact lens wearers, are as effective as earlier peroxide-based cleaners. In fact, some studies show that peroxide-based cleaners, which involve a two-step cleaning process and bubbling action to remove dirt and build-up, are better at killing certain types of organisms. But they are also more cumbersome to use than multi-purpose solution, which simply involves a rinse. "Manufacturers have wanted to produce solutions that are convenient and comfortable, but it may be a trade-off to a certain extent between convenience and efficacy," says Dr. Ehlers, an assistant professor at the University of Connecticut Health Center. Does that mean that consumers should go back to older types of cleaners? Dr. Ehlers says: "People ought to be having this conversation with their eye-care professional."

Another factor in last year's case that may resurface in this newest warning is how people misuse contact lenses and solution. Reusing or topping off old solution is a classic way to encourage infection. No-nos such as rinsing the inside of a contact case with water instead of solution, or showering or swimming while wearing lenses, may prove to be linked to the Complete MoisturePlus recall, since the parasite involved is water-borne. But the CDC's Roy is careful to point out that the investigation is still in its early stages, and little is known so far beyond the initial link. In the meantime, for the decision-averse, at least there's one less solution on the shelf to choose from.

For more information, visit the CDC's website