Contact lenses may alter the community of bacteria in the eyes, a new study has found.
All body sites including the mouth, gut and skin have normal bacterial community, which is expected to provide resistance and protection from harmful pathogens. The eyes are no exceptions.
Contact lenses are considered to be a risk factor for the occurrence of different eye infections such as keratitis and conjunctivitis. With this, researchers from New York University School of Medicine hypothesized that wearing contact lenses may be linked with alterations in the bacterial community of the eyes.
The Study
To investigate, the authors compared the bacterial communities of the conjunctiva and under-eye skin of 58 subjects and studied samples from 20 participants, of whom nine are contact lens wearers and 11 are non-wearers.
All in all, the team was able to collect 250 specimens via cotton swabs — 116 from the conjunctiva, 114 from under-eye skin and 20 from contact lenses.
The researchers compared the sample in three separate times using a laboratory method called 16s rRNA sequencing.
Bacteria-rich Eyes
The findings of the investigations have shown that there were more types of bacteria on the conjunctiva or ocular surface than on the under-eye skin — a result that is quite surprising according to corresponding author Maria Gloria Dominguez-Bello.
The bacterial community of the eye surface of contact lens wearers is more comparable to the skin than in non-wearers. The surface was rich with bacterial types such as Pseudomonas, Acinetobacter, Methylobacterium and Lactobacillus.
These bacteria were also present among non-wearers, but it was found more on the skin under the eye than on the eye surface itself, except for Lactobacillus. These people also had some bacterial types on the eye surface and these include Haemophilus, Neisseria, Streptococcus and Staphylococcus, among others.
In terms of the different time periods, the authors did not observe significant differences between the bacterial communities of the eye surface and under-eye skin.
Implications Of The Study
More than 30 million people in the U.S. wear contact lenses, according to records from the U.S. Food and Drug Administration.
This research may provide helpful insights for future studies that aim to explore the potential roles of the microbiome in the increased risk of eye infections among people who wear contact lenses.
Despite this, it may still be too early to give firm advice to contact lens wearers. "When we can better understand the mechanisms, we will be able to test hypotheses and propose preventive measurements," says Dominguez-Bello.
The study was published online in the journal mBio on Tuesday.
Photo: Mark Probst | Flickr
