Update on Contact Lens Eye Infection
CDC Issues Full Report on Contact Lens-Eye Infection Link
Aug. 22, 2006 -- Users of a recently recalled contact lens solution by Bausch & Lomb were more than 20 times as likely to develop a potentially blinding eye infection as nonusers.
The CDC study released today shows that 164 confirmed cases of the corneal infection Fusarium keratitis were reported in 33 states and a U.S. territory from June 1, 2005 to June 30, 2006. Ninety-four percent of those cases were among soft contact lens wearers.
When researchers compared the risk of infection among contact lens wearers, they found users of the recalled contact lens solution, ReNu with MoistureLoc, were more than 20 times as likely to develop the infection as nonusers.
Preliminary findings from this CDC investigation were released in May and prompted the withdrawal of ReNu with MoistureLoc from the market worldwide.
Where Did the Fungus Come From?
The complete report, published in JAMA, the Journal of the American Medical Association, provides further details of the link between a rare type of eye infection and the contact lens solution.
Fusarium is a fungus found in soil and plants. Beginning in March 2006, the CDC began to receive multiple reports of corneal infections caused by this fungus among contact lens wearers.
The condition is a serious complication that can lead to permanent vision loss or the need for a corneal transplantation. The cornea is the clear, thin layer of tissue that covers the iris (the colored part of the eye) and the pupil.
Overall, the study showed that 34% of the 164 corneal infection cases reported required corneal transplantation.
Researchers say it's still not clear what exactly caused the eye infections to develop. Testing of the factory where the contact lens solution is produced did not show evidence of the fungus.
The problem was likely due to outside contamination that did not occur during the manufacturing process, according to researcher Douglas C. Chang, MD, of the CDC, and colleagues.
They add it's unlikely the main cause for the outbreak could be poor contact lens hygiene habits.
"Ongoing studies may help to determine if the infections were caused by an interaction of its ingredients with Fusarium that might have permitted growth of the organism," conclude the researchers.
Meanwhile, users of Renu with MoistureLoc are urged to stop using the product; report any infections to their eye care professional; and pay careful attention to eye hygiene practices, including 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 lenses and contact lens solution products.