Likely Cause of ReNu with MoistureLoc Eye Infection Epidemic Revealed
Wednesday, November 12th, 2008Based upon data from a study published in the November 2008 issue of Archives of Ophthalmology, Renu with Moistureloc, manufactured by Bausch & Lomb, a contact lens solution that was implicated in an epidemic of the eye infection Fusarium keratitis between 2004 and 2006 was likely due to a reduction in the solution’s antifungal activity because of exposure to prolonged temperature increase.
In August 2004, Bausch & Lomb introduced ReNu with MoistureLoc, a contact lens solution that contains a unique antimicrobial agent. The solution was associated with cases of Fusarium keratitis, according to U.S. government reports, since March 2006. Eventually there were 154 confirmed cases identified in the United States of this condition characterized by inflammation of the cornea (keratitis). Bausch & Lomb investigators acknowledged that all original cases appear to be related to ReNu with MoistureLoc produced in their Greenville, South Carolina plant.
In 2006, the FDA inspected the Greenville facility and cited Bausch & Lomb for poorly controlling temperature in the production, storage and transport of products from this plant. Researchers further studied the effects of temperature on the growth of the Fusarium fungus by analyzing five contact solutions in addition to ReNu with MoistureLoc. The researchers explain that, 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).
Bausch & Lomb permanently removed its contact lens solution Renu with MoistureLoc from the market on May 15, 2006 due to an outbreak of extremely serious fungal eye infections called fungal keratitis, caused by the fusarium fungus. Bausch & Lomb had suspended shipments in April and asked retailers to stop selling the product. In February 2006, the company stopped selling ReNu with MoistureLoc in several Asian countries. The outbreak affected hundreds of contact lens wearers worldwide. Many victims of ReNu with MoistureLoc suffered partial or complete loss of vision in the affected eye(s) and were forced to undergo cornea transplantation surgery, with some requiring multiple cornea surgeries.
ReNu with MoistureLoc showed the greatest decline in anti-fungal activity after the 60-degree storage period, while Clear Care and ReNu MultiPlus demonstrated the smallest decline. The authors also specifically analyzed the strains of Fusarium that were linked to the keratitis epidemic. In addition, the authors of the study found that when stored at room temperature, ReNu with MoistureLoc allowed fungal growth in 27 of 84 different blends of isolates grown in different solutions and at different levels of dilution. When stored at 140 degrees Farenheit, the solution allowed fungal growth in 67 of 84 of these combinations.