The number of confirmed cases of a rare fungal eye infection that can cause blindness has climbed to 122, most of them contact-lens wearers who reported using Bausch & Lomb Inc.'s newest lens cleaner, US authorities said Friday.

Tanya Padashenko holds the world's first one-day disposable ultra-violet (UV) radiation protective contact lens at its launch in Sydney July 17. An analyst survey of independent optometrists suggests that half of those polled are advising patients to avoid all of Bausch and Lomb Inc.'s. [Reuters]

The eye-care company halted US sales of its ReNu with MoistureLoc MultiPurpose Solution a month ago after the Centers for Disease Control and Prevention said it was investigating an unusual spike in Fusarium keratitis infections in Americans using the product.

While the CDC reiterated in an update that the origin remains a mystery, some eye specialists theorized that MoistureLoc's unique disinfecting and moisturizing agents could have played a role in the outbreak, which first surfaced in the Far East.

"The general thinking now is we're seeing a loss of disinfecting capability as this solution absorbs into the lens," said Dr. Arthur Epstein, chairman of the American Optometric Association's contact lens and cornea section. "Somehow the disinfectant in the real world isn't doing what it's supposed to do."

The fungus is commonly found in plant material and soil in tropical and subtropical areas. Without eye-drop treatment, the infection can scar the cornea and blind its victims. At least eight US patients have required cornea transplants.

A bottle of ReNu contact lens solution is shown in this Tuesday, April 11, 2006 file photo in New York. Nearly two-thirds of contact-lens wearers who contracted a potentially blinding fungal eye infection reported using Bausch & Lomb Inc.'s newest lens cleaner, health authorities said Tuesday, May 9, 2006. [AP Photo]

On Tuesday, when it confirmed 106 infections, the CDC said 59 patients - or nearly two-thirds of the 93 fully analyzed cases involving contact lens users - reported using MoistureLoc. Another 19 patients said they used an older, more popular Bausch & Lomb solution called ReNu MultiPlus, it said.

The Atlanta-based agency said Friday that a breakdown of the 16 newly confirmed cases won't likely be revealed until next week.

In addition, the CDC said it has received 75 other reports of eye infections caused by Fusarium keratitis - of which 15 were "possible cases" and 60 were still under investigation.

Extensive federal inspections of the factory in Greenville, S.C., where MoistureLoc was made for US and several Asian markets before sales were halted April 13, have not turned up evidence of contamination.

While microbiologic tests could take another week or two to analyze, "one thing we are very close to deleting as a possibility is a widespread contamination in our plant," Bausch & Lomb's chief scientific officer, Praveen Tyle, said in an interview.

No infections have been reported in Japan or Canada, where MoistureLoc has never been sold, and infections dwindled in Singapore after MoistureLoc was pulled off shelves there in February, Tyle noted.

"We are looking more and more closely to patient habits and whether, when they're using MoistureLoc, they're more likely to get an infection compared with other products," Tyle said.

If MoistureLoc is implicated, he added, "the decision we really have to make is, `Can we bring this product back in its current forms in these markets, or do we have to tweak something ... in the formula and then bring back the tweaked formula?'"

Of the more than 30 million Americans who wear contact lenses, nearly 11 million use MultiPlus, which was launched a decade ago. Another 2.3 million people use MoistureLoc, which was introduced in late 2004 and accounted for $45 million in US sales last year. Bausch & Lomb also makes contact lenses, ophthalmic drugs and vision-correction surgical instruments and generates more than $2 billion in annual revenues.