More than a fourth of the contact lens users who suffered serious eye infections linked to Advanced Medical Optics’ recalled Complete MoisturePlus lens cleaner have required corneal transplants, according to an update on the outbreak released yesterday by federal health care authorities.

The use of a particular contact lens solution has a strong association with Acanthamoeba keratitis, a rare severe eye infection, report researchers at the University of Illinois at Chicago in a study published online this week by the American Journal of Ophthalmology. AK is an often severe, painful infection of the cornea that commonly causes corneal scarring and sometimes blindness.

Advanced Medical Optics said yesterday morning that it had no explanation yet of why its leading contact lens care product might be contributing to an outbreak of eye infections. And it said it would be next week before it could provide Wall Street with an estimate of the financial impact of its global recall of the lens cleaner.

Health officials and eye doctors are puzzled by an outbreak of a rare but potentially blinding eye infection that led the manufacturer of a contact lens cleaning solution to withdraw one of its products this weekend. The outbreak resembles one last year that was linked to a different manufacturer’s lens solution and a different microbe. In both instances, the cornea, the eye’s transparent outer covering, is at risk. But why two different microbes caused the outbreaks is not known.

A contact lens solution manufacturer voluntarily withdrew one of its products yesterday after federal health officials said an investigation had linked it to a rare but potentially blinding eye infection. Customers were advised to immediately stop using the solution, AMO Complete Moisture Plus Multi-Purpose Solution. The solution, used to clean and store soft contact lenses, is made by Advanced Medical Optics of Santa Ana, Calif. Advanced Medical Optics said it withdrew the product as a precaution after the epidemiologists at the disease control centers said they had identified 138 laboratory confirmed cases of the infection, Acanthamoeba keratitis, that have occurred throughout the country since January 2005. Keratitis is inflammation of the cornea.

Government officials are warning people to throw away a contact lens solution after an investigation linked it to a rare eye infection. The warning concerns AMO Complete Moisture Plus Multi-Purpose Solution, used for cleaning and storing soft contact lenses, said a spokeswoman for the U.S. Centers for Disease Control and Prevention. The solution seems to be a factor cases of Acanthamoeba keratitis, a painful eye infection that can lead to permanent vision loss or blindness.

The main threat is from legionnaires’ disease, which causes serious breathing difficulties. There have been five reported outbreaks linked to spa pools in the past five years, leading to four deaths. The flu-like Pontiac fever is also a risk.