Contact lenses can be worn to correct vision, or for cosmetic or therapeutic reasons. Many cases of potentially scarring bacterial keratitis, or eye inflammation, as well as conjunctival infections occur among those who use contact lenses. A new study has found that wearing lenses can cause more infections in the eyes as compared to those who do not wear them.
Researchers at NYU Langone Medical Center used high-precision genetic tests to differentiate the thousands of bacteria that make up the human microbiome. They found that the eye surface, or conjunctiva, has surprisingly higher bacterial diversity than the skin directly beneath the eye. Three times the usual proportion of Methylobacterium, Lactobacillus, Acinetobacter and Pseudomonas bacteria were identified on the eyeballs of the study's nine contact lens wearers.
When measured and plotted on a graph, statistical germ diversity scores showed that the eye microbiome of contact lens wearers had a composition more similar to that of the wearer's skin than the eye microbiome of non-lens wearers. More Staphylococcus Bacteria, which are linked to eye infections and are more prominent on the skin, were found in the eyes of non-lens wearers, and researchers do not yet have an explanation for the disparity.
Senior study investigator and associate professor Maria Gloria Dominguez-Bello, said, "We still have to figure if these changes were 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."
The study was presented at the annual meeting of the American Society for Microbiology in New Orleans.