Government officials are warning people to throw away a contact lens solution after an investigation linked it to a rare but serious eye infection.

The warning concerns AMO Complete Moisture Plus Multi-Purpose Solution, which is used for cleaning and storing soft contact lenses.

The infection, Acanthamoeba keratitis, is caused by a parasite.

The link between the solution and the infection was identified as a result of an investigation by the Centers for Disease Control and Prevention.

The CDC is concerned the solution may be a factor in a painful eye infection that can lead to permanent vision loss or blindness. The CDC and the Food and Drug Administration are investigating 138 confirmed cases.

Officials said people should discard the solution, throw out their current contact lenses and toss the lens storage case. They need to get rid of all partially used or unopened bottles. All of them may harbor the infecting amoeba.

The solution is made by Advanced Medical Optics, a California firm.

Acanthamoeba keratitis may lead to vision loss with some patients requiring a corneal transplant. The infection primarily affects otherwise healthy people who wear contact lenses.

Consumers should ask their doctor about choosing an appropriate alternative cleaning/disinfecting product and seek immediate treatment if they have symptoms of eye infection as early diagnosis is important for effective treatment, according to the CDC.

The symptoms of Acanthamoeba keratitis can be very similar to those of other more common eye infections and may include eye pain or redness, blurred vision, light sensitivity, sensation of something in the eye or excessive tearing, but Acanthamoeba is more difficult to treat.

It is estimated that Acanthamoeba keratitis infections occur in approximately 2 out of every 1 million contact lens users in the United States each year. However, in a multi-state investigation to evaluate a recent increase in Acanthamoeba keratitis cases, CDC determined that the risk of developing AK was at least seven times greater for those consumers who used Complete MoisturePlus solution versus those who did not.

Additional information regarding the CDC results is available at the CDC Web site.

"The ongoing CDC investigation is a collaborative effort," said Dr. Michael Beach, a Division of Parasitic Diseases team leader with CDC. "We are working with FDA, state, territory, university, and clinical partners in an effort to further understand whether usage or contamination of this solution led to these Acanthamoeba infections."

According to the CDC, all contact lens users should closely adhere to the following measures to help prevent eye infections:

Remove contact lenses before any activity involving contact with water, including showering, using a hot tub, or swimming.

Wash hands with soap and water and dry them before handling contact lenses.

Clean contact lenses according to manufacturer guidelines and instructions from an eye care professional.

Use fresh cleaning or disinfecting solution each time lenses are cleaned and stored. Never reuse or top off old solution.
Never use saline solution and rewetting drops to disinfect lenses. Neither solution is an effective or approved disinfectant.

Schedule regular eye exams with your eye care professional

Wear and replace contact lenses according to the schedule prescribed by your eye care professional.

Store lenses in a proper storage case.

Storage cases should be irrigated with sterile contact lens solution (never use tap water) and left open to dry after each use.
Replace storage cases at least once every three months.

FDA and CDC want to gather information related to Acanthamoeba keratitis in contact lens users. Report adverse events related to these products to MedWatch, the FDA's voluntary reporting program: www.fda.gov/medwatch/report.htm; Phone: 800-332-1088; Fax: 800-332-0178; Mail: MedWatch, Food and Drug Administration, 5600 Fishers Lane, Rockville, MD, 20852-9787.

Consumers who believe they are in possession of the recalled product may call the company at 1-888-899-9183.