Over the summer, a Food & Drug Administration (FDA) advisory panel recommended that contact lens solutions be subjected to more stringent testing than what is currently required. The recommendation came after several brands of contact lens solution, including Bausch & Lomb’s Renu with MoistureLoc, were tied to potentially-blinding eye infections.
Bausch & Lomb issued a worldwide recall of Renu with MoistureLoc Contact Lens Solution after it was linked to hundreds of cases of Fusarium Keratitis, a rare, but serious infection of the cornea that has the potential to cause blindness. Risk factors for infection usually include trauma (generally with plant material), chronic ocular surface diseases, immunodeficiencies, and, rarely, contact lens use.
Fungal keratitis is a condition more prevalent in warm climates. First-line treatment includes topical and oral antifungal medications. Patients who do not respond to treatment usually require surgical intervention, including corneal transplantation. These infections are not transmitted from person to person.
On April 10, 2006, the FDA and the Centers for Disease Control (CDC) issued public health warnings concerning serious fungal infections associated with contact lens solution use. The CDC stated that it had interviewed 30 patients suspected of having fungal keratitis. Of these 30 patients, 28 wore soft contact lenses and 26 used a Bausch & Lomb ReNu contact lens solution in the month prior to the fungal infection diagnosis.
On April 13, 2006, Bausch & Lomb, Inc. recommended that consumers switch to another lens care solution and asked all retailers to remove U.S. manufactured Renu with MoistureLoc from their shelves. On May 2, 2006 the CDC announced that the number of confirmed fungal infections rose to 88 cases. Just three days later, on May 5, 2006, the CDC revised the number of confirmed cases to 102.
On May 12, 2006, the CDC made another upward revision in the number of confirmed fungal eye infections to 122 cases. On May 15, 2006, the FDA issued a press release stating: “Based on this scientific and epidemiological data suggesting that Renu with MoistureLoc may increase susceptibility to Fusarium, Bausch & Lomb has decided to permanently remove the Renu with MoistureLoc product worldwide.”
Bausch & Lomb, Inc. and the FDA both acknowledged that there was a problem in the chemical properties of Renu with Moisture that prevented the disinfectant in the product from killing the Fusarium fungus. Testing had had confirmed that the Renu with MoistureLoc solution allowed a polymer film to form around the Fusarium fungus that made it resistant to the disinfectant in the product.
Renu with MoistureLoc was just one of several contact lens solutions linked to serious eye infections. Last year, at least 21 cases of infections involving the water-borne Acanthamoeba parasite were linked to Advanced Medical Optics (AMO) Complete MoisturePlus solution, prompting the Santa Ana, California-based company to recall the product.
That AMO recall followed another issued in November 2006, when 2.9 million packets of AMO Complete MoisturePlus Multi-Purpose contact-lens solution and Active Packs were recalled after lots sold in Japan were found to have bacterial contamination. The recall included 183,000 Complete MoisturePlus units sold in the United States. AMO traced the contaminated units to a plant in China and found that Ralstonia bacteria had compromised the disinfectant in the solution and were eating away at the oxygen in the bottles.
Since the outbreaks and recalls, critics of contact lens solution makers have contended that current testing methods are not enough to insure the products’ safety. That argument gained added weight earlier this year when researchers at the Center for Medical Mycology found ReNu with MoistureLoc was unable to resist contamination because the strain of Fusarium responsible for the 2006 outbreak had the ability to form biofilms.
Biofilms are clusters of microbes held together by a glue-like matrix. This structure made the Fusarium extremely resistant to contact lens solutions and the body’s own immune system. Unfortunately, contact lens solutions are not required to be tested against microbes with the ability to form biofilms. In fact, Renu with MoistureLoc and other contact lens solutions are tested against a rare type of fungus obtained from a patient in Nigeria in 1970s, which critics say has no real-world applicability.
In the case of the recalled AMO contact lens solution, there is no requirement at this time for solutions to be tested against Acanthamoeba. Following the 2007 recall, researchers found that AMO Complete MoisturePlus had no ability to kill the parasite.
The contact lens solution recalls have increased calls for the FDA to update the safety regulations that now govern the way the products are sold and tested. This past June, an FDA advisory panel took up the issue, and strongly recommended that the agency revamp testing requirements for contact lens solutions. The panel also recommended a variety of strong new consumer warnings for the products, including cautions that reusing lens solution can lead to blindness. The FDA is not bound to follow recommendations of advisory panels, but in most cases, it does so.