MoistureLoc formula at root of Fusarium outbreak

An undetermined interaction between Bausch & Lomb’s ReNu with MoistureLoc contact lens solution, the Fusarium fungus and possibly contact lenses or contact lens cases caused the US outbreak of Fusarium keratitis, according to researchers from the US Centers for Disease Control and Prevention (CDC).

Writing in this week’s Journal of the American Medical Association, Dr Douglas Chang of the epidemiology unit at CDC, and colleagues identified 164 confirmed cases in 33 states. The article aimed to define specific activities, contact lens hygeine practices or products associated with the Fusarium outbreak.

Although MoistureLoc distributed to the US, Hong Kong and Singapore all originated from the same manufacturing plant in Greenville, South Carolina, the report said it is unlikely that these cases were caused by ‘intrinsic contamination of the solution itself’.

‘Our findings ... suggest that exposure was likely the result of extrinsic contamination of contact lens solution bottles or lens cases occurring outside of the manufacturing or storage processes, perhaps in patients’ homes.’

However, the report stops short of saying that poor lens hygeine was to blame: ‘sub-optimal contact lens hygeine practices appear unlikely as the major explanation for the outbreak’.

‘It appears that this outbreak may have been caused by a complex and, as yet, undetermined interaction between MoistureLoc, Fusarium, and possibly the lens case or contact lens. Unique properties of MoistureLoc formula may have contributed to fungal infection following this type of contamination.’ These properties stem from the inclusion of two ingredients not found in any other contact lens solution: alexidine and polyquarterium 10.

The article concluded that Fusarium keratitis with substantial morbidity ‘was associated with use of a specific contact lens solution, MoistureLoc.’

Bausch & Lomb meanwhile focused on the CDC’s conclusion that the eye care corporation was right to recall the product when it did.

‘Our intense and extensive investigation into the Fusarium situation, combined with scientifically rigorous independent reports such as the CDC’s, has produced an exceptional body of valuable intellectual property that we will use to develop new and innovative products to meet the needs of consumers and eye care practitioners,’ said Bausch & Lomb in a statement.