ReNu with MoistureLoc loses much of its ability to fight fungal contamination when exposed to high temperatures for a long period of time, according to a new study published in the Archives of Ophthalmology. ReNu with MoistureLoc was recalled by Bausch & Lomb in 2006, after it was implicated in massive outbreak of the potentially-blinding fungal infection, Fusarium Keratitis. Following the ReNu with MoistureLoc recall, the Food & Drug Administration (FDA) cited the company’s Greenville, S.C. plant for inadequate temperature control in the production, storage and transport of the contact lens solution.
Bausch & Lomb pulled ReNu with MoistureLoc from Asian markets in February 2006, and did the same in the U.S. in April, before finally issuing a worldwide recall on May 15, 2006. A Centers for Disease Control (CDC) report found that those infected with Fusarium Keratitis were 20 time more likely to have used the ReNu with MoistureLoc solution. The CDC report determined that bad hygiene habits among users were not to blame for the infections, but that the contact lens solution appeared to have poor disinfectant qualities.
Recently, researchers at Wright State University Boonshoft School of Medicine in Dayton, Ohio, tested ReNu with MoistureLoc and five other contact lens solutions. ReNu with MoistureLoc contains a microbial agent not found in other contact lens solutions.
“Two bottles of each solution were separately stored at room temperature and 60 degrees Celsius (140 degrees Fahrenheit) for four weeks, serially diluted and then tested for their ability to inhibit growth of 11 Fusarium isolates [seven of which were associated with the keratitis epidemic],” the researchers wrote.
ReNu with MoistureLoc showed the greatest decline in antifungal activity when stored at 60 degrees C. ReNu with MoistureLoc allowed growth of Fusarium strains associated with the outbreak in 27 of 84 combinations when stored at room temperature. The number rose to 67 of 84 combinations when stored at 60 degrees C.
The study authors wrote that their research did not determine the exact temperature, length of exposure to elevated temperature and extent of temperature fluctuation that would cause a reduction in the antifungal properties of any of the solutions tested. But they concluded that their findings, “coupled with the FDA reports of Bausch & Lomb’s failure to regulate the storage and transport temperatures of the products manufactured in their Greensville plant, may be significant.”