Artificial tears contamination risk

Multiple-use packs of preservative-free artificial tears are susceptible to contamination, according to study results published in the November issue of the British Journal of Ophthalmology.

Dr C Y Choi of the Department of Ophthalmology at Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, 108, Pyeongdong, Jongnogu, Seoul, Republic of Korea and colleagues cultured the fluid remaining in multiple-use bottles (n=242) of both preservative-free and preservative-containing artificial tears after ≥3 administrations per 10 hours.

The team found microbial contamination in 2.0% of the bottles (n=5). All contaminations were found in bottles containing the preservative-free tears, and were either coagulase-negative staphylococcus or gram-negative acinetobacter. After multivariate regression analysis it emerged that age and fingertip touch were the factors with the greatest influence on contamination rates.

The researchers concluded that resealable packs of preservative-free artificial tears, especially when used by older patients and/or when fingertip touch was significant, are prone to infection in daily and multiple use settings.