It started with a yellow discharge. How doctors diagnosed an eye infection linked to recalled eyedrops

How a rare type of bacteria infected and ultimately blinded Nancy Montz's left eye was a head-scratcher for Dr. Morgan Morelli, a physician who specializes in infectious diseases.

The Ohio woman had been infected with Pseudomonas aeruginosa, a bacterium resistant to most antibiotics. Morelli, chief fellow in the division of infectious diseases and HIV medicine at the University Hospitals Cleveland Medical Center, had never seen this kind of bacteria in an eye.

In fact, the particular kind of highly drug-resistant bacterium had never been reported in the United States.

"We were racking our heads trying to figure out how this happened," she said.

Montz, 72, of Perry, did not wear contacts — a common route for bacteria to enter the eyes. Last November, in chilly northeastern Ohio, she certainly hadn't been swimming in any nearby lakes, another potential source of unusual bacteria.

"We thought that this was just some sort of freak accident," Morelli said. "We had no idea that this case was going to be linked to a global manufacturing issue."

It took several months to confirm that Montz's infection had come from a contaminated bottle of EzriCare artificial tears, a product since linked to dozens of similar eye infections nationwide.

Details of Montz's case were published Thursday in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology.

As of March 14, at least 68 people in 16 states had been diagnosed with such eye infections, according to the Centers for Disease Control and Prevention.

Eight patients, like Montz, lost vision in at least one eye. Four people had to have their eyeballs surgically removed. Three have died.

EzriCare Artificial Tears, as well as Delsam Pharma's Artificial Eye Ointment, were recalled in February. The products had been manufactured by Global Pharma Healthcare in India and sold mostly online.

The CDC expects more cases will be identified and plans to update its investigation into the cases in the coming weeks, a spokesperson said. The agency confirmed to NBC News that Montz is one of 68 patients so far in its ongoing investigation.

Montz's infection was advanced when it was diagnosed, and she is unlikely to see out of that eye again.

She first realized something was wrong when she woke up with an unusual smear of yellow discharge on her pillow. Her left eye was cloudy and she had trouble seeing out of it.

The eye was "real funky looking," Montz said. She couldn't feel any pain or soreness, however, because a prior health problem had numbed the entire left side of her face, including her left eye.

Her husband encouraged her to see a doctor, who prescribed antibiotics.

But the drugs, which almost always take care of eye infections, didn't work. Within 48 hours, her eye became much worse. That's when Morelli got involved.

Her team ultimately found the bacteria that had infected Montz's eye was also in the bottle of EzriCare artificial tears she'd ordered through Amazon.

"She probably scratched the left eye with the eyedropper accidentally and didn't realize it because she had no feeling," Morelli hypothesized. "That allowed the infection to enter the eye much more easily and quickly in that eye before it ever affected the right one."

Morelli recommended several ways to reduce the risk of any type of eye infection:

Wash your hands well before taking the top off of the bottle.

Keep the tip of the dropper as sterile as possible. Do not touch it with your fingers or allow it to come into contact with any other surfaces before replacing the cap.

Avoid using eyedrop bottles that are refillable.

Throw away expired products.

Only use artificial tears and other eyedrops that your doctor recommends.

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This article was originally published on NBCNews.com