People who wear contact lenses could experience an increase in certain types of eye infections due to changes to the surface of their eye that increase the bacterial diversity in that area, a team of researchers from the NYU Langone Medical Center has discovered.
The researchers, who presented their findings Sunday at the annual conference of the American Society for Microbiology (asm2015) in New Orleans, used high-precision genetic tests to find the differences between the thousands of bacteria that comprise the human microbiome.
In the course of their work, they found a possible and somewhat surprising reason why contact lens wearers tend to get more eye infections on a daily basis: a diverse set of microoganisms in the eyes of these individuals changes to become more similar in nature to that normally found in the skin of the eyelid than the bacteria in the eyes of non-lens users.
Seeking the root cause of these microbiome changes
The study authors explained that the eye surface, also known as the conjunctiva, of contact lens users has three times as many Methylobacterium, Lactobacillus, Acinetobacter, and Pseudomonas bacteria than is typically found in the eyeballs of people who do not wear contacts.
The NYU Langone team’s findings are based on an examination and comparison of the eyes of nine men and women who regularly use contact lenses, and 11 others who do not wear them. They also found that the composition of a lens-user’s eye microbiome was more similar to that of their own skin than to the eyes of people who do not wear contacts.
“Our research clearly shows that putting a foreign object, such as a contact lens, on the eye is not a neutral act,” Dr. Maria Gloria Dominguez-Bello, a microbiologist and associate professor at NYU Langone and senior investigator on the study, explained in a statement. “These findings should help scientists better understand the longstanding problem of why contact-lens wearers are more prone to eye infections than non-lens wearers.”
“What we hope our future experiments will show is whether these changes in the eye microbiome of lens wearers are due to fingers touching the eye, or from the lens’s direct pressure affecting and altering the immune system in the eye and what bacteria are suppressed or are allowed to thrive,” she added.