CDC study confirms Fusarium link to contact lens solution

While the published study by a group of physicians led by the Centers for Disease Control and Prevention (CDC) offers few new conclusions about the fungal infection, it does provide some closure to the outbreak that baffled investigators worldwide.

The U.S. cases followed reports, beginning in February, from Hong Kong and Singapore, where initial findings linked the cases to contact lens wearers who used a Bausch & Lomb ReNu brand contact lens solution. The report details the steps taken to evaluate the contact lens solution and its manufacturing processes. (See the May 15, June 1, June 15, and July 1 issues of Ophthalmology Times.)

The report also outlines a case-control study of 45 patients matched to one or two of 78 eligible controls.

"The multivariable model of single-solution users . . . identified only the use of MoistureLoc in the month before symptom onset as significantly associated with having Fusarium keratitis . . . ," the study stated.

Douglas C. Chang, MD, Epidemic Intelligence Service officer for the CDC and the report's primary author, said a study of the genetic isolates supports the idea that there was no single contaminant.

"We think the fact that our isolates were broad suggests that the Fusarium was acquired in patients' homes or communities rather than a single source," Dr. Chang said.

As was suspected when Bausch & Lomb pulled the ReNu with MoistureLoc solution from the U.S. market on April 13 and worldwide on May 15, the source is thought to be a combination of suboptimal contact lens hygiene practices and unique properties of the MoistureLoc solution.