Contact lenses increase the susceptibility to eye infections

Contact lenses affect the microbiome in the eye
Contact lens wearers show an increased risk of bacterial eye infections, which is due to the changing diversity of bacteria in the eye, according to US scientists at the NYU Langone Medical Center. Wearing contact lenses significantly increases the number of bacteria and increases the likelihood of infection, according to the research team led by microbiologist Maria Gloria Dominguez-Bello.

The US scientists found that on the surface of the eye and conjunctiva in general there is a surprisingly higher bacterial diversity than on the skin directly under the eye. In addition, the contact lens wearers examined in the current study had shown three times the average number of certain bacteria in the tear fluid and on the conjunctiva. In its composition, the microbiome in the eye of the contact lens wearer would have tended to be more suited to the bacterial composition on the skin than to the non-contact lens wearer, the researchers report.

By wearing contact lenses, the microbiome of the eye changes and the risk of eye infection increases. (Image: Africa Studio / fotolia.com)

Certain bacteria in the contact lens wearer significantly more common
According to the scientists, significantly more bacteria of the genera Methylobacterium, Lactobacillus, Acinetobacter and Pseudomonas were detected in the eye of the study's nine contact lens wearers than in the eleven non-lens wearers. In addition, the composition of the microorganisms in the tear fluid of the contact lens wearer showed significant similarities to the bacterial flora on the eyelid, which was not the case in the subjects without contact lenses. "Our research clearly shows that the insertion of a foreign body such as a contact lens on the eye is not a neutral act," says Maria Gloria Dominguez-Bello. The microbiome of the eye is influenced by the lenses lasting.

Altered microbiome an explanation for the increased risk of infection?
In the study, the researchers used swabs to take samples from various parts of the eye, including the conjunctiva and the skin just below the eye, and perform a high-precision analysis of the genetic material. The observed differences between lens wearers and non-contact subjects may, according to the researchers, account for the increased susceptibility of contact lens wearers to ocular infections. However, the scientists also came to the surprising conclusion that in subjects without contact lenses more bacteria of the genus of staphylococci were detected in the eye, which are actually known as potential triggers of eye infections. How to evaluate this, further research will now show.

Take hygiene into account when using contact lenses
So far, it remains unclear, which causes the changes in the bacterial flora in the eye in the contact lens wearers. We hope that our future experiments will explain whether these changes are due to touch with the fingers or associated entry of bacteria, or whether the pressure from the lens directly affects the immune system in the eyes, according to Dominguez-Bello. Current results suggest that eyelid and hand hygiene should be given more attention when using contact lenses, as changes in bacterial flora in the eye appear to be skin-derived, adds co-study author Professor Jack Dodick of the NYU Langone Medical Centers , (Fp)