Wearing contact lenses may raise the risk of infections by colonizing the eye surface with bacteria that belongs on the skin, according to new research.
A new study, conducted at New York University, reveals evidence that contact lenses change the eye microbiome by making it more "skin-like."
The study involved data from 58 participants. Researchers used a technique called 16s rRNA sequencing to analyze bacterial communities on the eye surface and skin under the eyes of participants. Researchers also took additional measurements from 20 individuals at three time points over the course of six weeks. They noted that nine of the 20 individuals wore contact lenses and the other 11 did not.
After analyzing 250 samples taken from participants, researchers found significantly higher proportions of the skin bacteria Pseudomonas, Acinetobacter, Methylobacterium and Lactobacillus and signficantly lower proportions of Haemophilus, Streptococcus, Staphylococcus and Corynebacterium on the eye surface of participants who wore contact lenses compared to those who did not wear contact lenses.
Analysis also revealed that the eye surfaces of participants who wore contact lenses contained significantly more types of bacteria than on the surfaces of their lenses and skin underneath their eyes.
"Compared to those from non-lens wearers, dry conjunctival swabs from lens wearers had more variable and skin-like bacterial community structures, with higher abundances of Methylobacterium, Lactobacillus, Acinetobacter, and Pseudomonas and lower abundances of Haemophilus, Streptococcus, Staphylococcus, and Corynebacterium," the researchers wrote in the study.
"The results indicate that wearing contact lenses alters the microbial structure of the ocular conjunctiva, making it more similar to that of the skin microbiota. Further research is needed to determine whether the microbiome structure provides less protection from ocular infections," they added.
Researchers said that the latest findings may provide insight into how bacterial communities on eye surfaces contribute to eye infection and disease. Previous studies have linked contact lenses to an increased risk of giant papillary conjunctivitis and keratitis.
"Our study has the potential to help future studies explore novel insights into a possible role of the microbiome in the increased risk for eye infections in contact lens wearers," said senior study author Maria Dominguez-Bello, an associate professor of medicine at New York University, according to a news release.
"As in other body sites (i.e., the gut, skin, and mouth), the eye has a normal community of bacteria which are expected to confer resistance that provides protection from invaders. However, the eye microbiome has been largely neglected and is relevant to eye health and understanding eye diseases and to discovery of its functions. This report of a baseline study shows differences in the eye microbiome of contact lens wearers in relation to those of non-lens wearers and has the potential to help future studies explore novel insights into a possible role of the microbiome in the increased risk for eye infections in contact lens wearers," the researchers concluded.
The findings are published in the journal mBio.
