The Centers for Disease Control and Prevention is investigating 109 reports of Fusarium keratitis infection in patients in 17 states since June 2005.
Federal and state health officials have interviewed just 30 of those patients. However, of the 28 who wore soft contact lens, however, 26 reported using Bausch & Lomb's ReNu brand contact lens solution or a generic type of solution also made by the Rochester, N.Y., company.
Bausch & Lomb said it would temporarily suspend shipments of ReNu with MoistureLoc made at its Greenville, S.C., plant.
"The CDC data released today are both troubling and perplexing, as there is an apparent disproportionate representation of U.S.-manufactured ReNu with MoistureLoc in the underlying data. The source of these infections has not been determined," company chairman and chief executive officer Ronald Zarrella said.
Five of the 26 patients also reported using other types of solutions in addition to ReNu, Bausch & Lomb said. And nine said they wore their lenses overnight, which is known to increase the risk of infection, the CDC said.
Dr. Daniel Schultz, director of the Food and Drug Administration's Center for Devices and Radiological Health, said it was too early to determine if Bausch & Lomb's solution was the cause of the infections. Both the FDA and CDC are investigating a growing number of reports of infection by the fungus. An estimated 30 million Americans wear soft contact lenses.
"We are relatively early in this investigation. It may be we will find this particular product does not have an association. We may find a strong association," Schultz told reporters.
The fungus is commonly found in plant material and soil in tropical and subtropical areas. Singapore health officials noticed an increase in reports of infection in January and discovered 39 cases involving contact lens users from 2005 to February of this year. Cases have also been reported in Malaysia and Hong Kong.
In February, Bausch & Lomb halted sales of its ReNu contact lens solution in Singapore and Hong Kong.
Without treatment, which can last two to three months, the infection can scar the cornea and blind its victims. Eight U.S. patients have required cornea transplants.
Soft contact users with eye redness or pain, tearing, increased light sensitivity, blurred vision or discharge should stop wearing contacts and contact a doctor immediately, said Dr. Malvina Eydelman, director of the FDA's Division of Ophthalmic and Ear, Nose and Throat Devices. The FDA also advises users to wash their hands well with soap and water before handling lenses and to follow cleaning and storage guidelines.
In addition, contact lens wearers who use ReNu with MoistureLoc should do so with caution, the FDA said.