But investigators knew that the common link between the cases was Bausch & Lomb ReNu contact lens cleaner with MoistureLoc.
Now, there may finally be a cause. a team of researchers at the Wright State University Boonshoft School of Medicine in Dayton, Ohio, says high temperatures at the processing plant could be to blame
They compared 2 bottles of the lens solution - one kept at room temperature, the other kept at 140 degrees Fahrenheit. They found that the heated solution wasn't able to control fungal activity as well as the solution kept at room temperature.
The South Carolina factory where the suspect solution was processed was cited in 2006 by the Food & Drug Administration for inadequate temperature controls.
But, the FDA, and eye experts didn't realize at the time temperature could cause the problem.
About 200 people reported cases of fusarium keratitis.
The report says, "Knowledge of the potential loss of antimicrobial activity of contact lens solutions and other pharmaceutical products when exposed to higher temperatures and the risk of such exposure when storing and transporting those products may help prevent such epidemics in the future."