Earlier this year, the Centers for Disease Control and Prevention received multiple reports of Fusarium keratitis among contact lens wearers in the US.

Corneal infection (Fusarium keratitis) or microbial keratitis is a rare but serious complication that may lead to permanent vision loss or the need for corneal transplantation. Among the 34 million contact lens wearers in the United States, The annual incidence of microbial keratitis is estimated to be 4 to 21 per 10,000 soft contact lens wearers depending on overnight wear.

Fusarium is a filamentous fungus commonly found in soil and plants and is the major cause of fungal keratitis in certain tropical or subtropical regions.

The recent outbreak of this cornel infection in the United States earlier this year has been found to be associated with the use of a specific contact lens solution, ReNu with MoistureLoc.

When the preliminary findings from the case investigation were released in May, the said product was withdrawn from the market worldwide.

According to the authors of the study:

"Other products, including ReNu MultiPlus, private label Multiplus were not associated with Fusarium keratitis compared with nonusers of those solutions.

Our findings, together with the results of environmental testing, suggest that exposure to Fusarium 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, suboptimal contact lens hygiene practices appear unlikely as the major explanation for the outbreak.

The said study was reported in the August 23/30 issue of JAMA.

While ongoing studies may help in the determination whether the infections were caused by an interaction of ReNu with MoistureLoc ingredients with Fusarium that might have permitted growth of the organism, clinicians should be vigilant in their diagnosis and treatment of fungal keratitis.

Meanwhile the users of ReNu MoistureLoc should discontinue the use of this product.

The researchers of this study warned that users of soft contact lens should strictly follow the instructions of their ophthalmologist (or other eye-care professional) and continue to pay careful attention to optimal hygiene practices: washing and drying hands prior to handling lenses, storing lenses in new contact lens solution after each use, and carefully following directions for use of contact lens and contact lens solution products.

Source: Science Daily