U.S. officials recently reported two more deaths and additional cases of vision loss linked to eye drops tainted with drug-resistant bacteria — with the CDC identifying the issue now in 16 states, including California, New York, Illinois, Texas and Pennsylvania. 

Most cases have been linked to four regional clusters. EzriCare's drops are the only product used by patients in each group, the Associated Press reported.

The eye drops from EzriCare and Delsam Pharma were recalled in February — and health authorities are continuing to track infections as they investigate the outbreak.

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The recalled drops were manufactured by Global Pharma Healthcare in India, where the bacteria — Pseudomonas aeruginosa — is commonly linked to outbreaks in hospitals. 

Dr. James Kelly, M.D., an ophthalmologist based in New York City and founder of Kelly Vision Center, appeared on "Fox & Friends Weekend" on Saturday to discuss the outbreak of the drug-resistant bacteria linked to eye drops.

eye drops

The "contamination where sterility" was "compromised could have happened anywhere" in the production process of getting eye drops to the consumer.  (iStock)

"The investigation is ongoing," said Kelly on Saturday morning. 

"So the contamination where sterility is compromised — it could have happened anywhere, from the manufacturing to the packaging to the handling to the storing. At any of those points, contamination can occur."

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He added, "I don't think it's known yet. So we will eventually find out."

The doctor also said, "Unfortunately, we never think of eye drops as being something that could cause this type of [infection or] have lethal consequences. In this particular instance, the bacteria [are] very drug-resistant bacteria."

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He also described the bacteria as "very aggressive."

human eye

People at home can take certain measures to decrease the chances of bacteria spreading as they use eye drops. Among other tips: Wash hands before applying eye drops. Then, carefully inspect the bottle before use. (iStock)

Kelly reiterated, "Where the contamination happened, no one's really clear about that."

Even so, he said there are specific measures that people at home can take to decrease the chances of contamination spreading or harming them. 

Smart steps to take regarding eye drop use

"Before you use eye drops, wash your hands," said Kelly.

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He also said, "Inspect the bottle, actually. Look for any visible contamination or within the liquid contents of the bottle."

Then, he said, once the bottle of eye drops is uncapped, people should not allow "the tip of the bottle" to touch or come in contact with "any surface."

Woman putting in eye drops

After using eye drops, promptly recap the bottle "and store it in a clean, dry location," said Dr. James Kelly of Kelly Vision Center. (iStock)

Instead, said Kelly, "Just allow the drop to go directly into [the] eye."

Then, he said, promptly "recap it and store it in a clean, dry location."

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The doctor also said that "expiration dates matter. We know that the effectiveness of a medication is less after the expiration date. The risk of contamination is higher — so look at the expiration date on your medicine, especially eye drops."

Kelly also said that anyone who is experiencing "any kind of pain, light sensitivity, blurry vision or discharge" should "seek immediate medical care."

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The Associated Press contributed to this report.