Artificial tears: Beware of microplastics

Microplastics have been detected in disposable artificial tears on the market, and a study has shown that to reduce the amount entering the eyes, the product should be held upside down when removing the cap.

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If artificial tears are used immediately after opening, there is a risk that microplastics may enter the eyes, so caution is advised. For this reason, the Ministry of Food and Drug Safety recommends discarding the first one or two drops of artificial tears before use. However, it was not clear how much microplastic is contained in the first one or two drops.

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Therefore, a joint research team including Professor Kim Dong-hyun of the Department of Ophthalmology at Korea University Anam Hospital and Director Jung Jae-hak of the Korea Analysis Science Institute conducted a study on five commercially available hyaluronic acid-based artificial tears to determine how much microplastic is contained in artificial tears.

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The research team analyzed the microplastic content of artificial tears by removing the cap while holding it upright and discarding the first drop, removing the cap while holding it upside down and dropping two drops, and removing the cap while holding it upside down and discarding about half, then dividing the remaining solution. Raman spectroscopy and scanning electron microscopy were used for the analysis.

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Analysis showed that microplastics were not detected in the remaining solution after discarding about half. When the artificial tears bottle was held upright and the cap was removed, the first drop contained 0.50 ± 0.65 microplastic particles per 30 mL. The remaining solution contained 0.75 ± 0.72 particles per 30 mL. After discarding two drops while inverted, the remaining solution contained 0.14 ± 0.35 particles per 30 mL. Results were similar for both single-use and reusable bottles.

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In summary, to reduce microplastic exposure, you should hold the artificial tears upside down, remove the cap, pour out about half of the solution, and then use it. Professor Kim Dong-hyun explained, "Most of the microplastics in artificial tears are released when the cap is removed," and added, "By removing the cap while holding the artificial tears upside down, gravity can prevent the microplastics from falling into the solution."

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He also said, "If you discard about half of the solution before use, it seems that the small amount of microplastics generated inside the container are also removed," and "Since the Korea Food and Drug Administration recommends using artificial tears only once, it would be better to discard about half of the solution before use."

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According to the research team, if an individual instills the first drops of artificial tears four times a day for one year, they could be exposed to a total of 730.0 microplastic particles. Discarding the first two drops before use can reduce this number to 204.4.

Meanwhile, microplastics refer to small plastics less than 5 mm in size. It has been known that when broken down to the nano level and absorbed by cells, they can exhibit toxicity. The impact on eye health has not yet been determined. Professor Kim Dong-hyun stated, "Microplastics have been found in the conjunctiva (nictitating membrane) of the eye as well as in residues after cataract surgery, indicating that further research is urgently needed."

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Recently, a study conducted by a Singaporean research institution on all artificial tear products on the market found that microplastics were detected in all of them.

Microplastics that enter the eyes are said to travel along the tear ducts all the way to the lungs.

They say you should definitely drop the small beads to use less!!