Intestinal microbiomes are a common subject in the medical community, but a recent discovery has found a reason to focus on eye microbiome and disease. They’ve proven the presence of beneficial ocular bacteria. Dr. St. Leger explains: Why it is only under the eyelid that home for bacteria is suitable. How tears keep most bacteria away yet coexist with beneficial bacteria. Near-term research that might lead to drugs that use bacteria for eye microbiome and disease treatment. Anthony St. Leger is an assistant professor of Ophthalmology and Immunology at the University of Pittsburgh School of Medicine. He began this ocular study after working on a diseased eye of a mouse in which they found beneficial bacteria, a type that seemed to function like our gut microbiome: these bacteria seemed to moderate the vulnerability to infectious disease and work toward the host’s immunity. Dr. St. Leger’s lab then began to fully research these resident bacteria and their potential to inhibit viral infections among other actions. Dr. St. Leger discusses the entire eye landscape, explaining why the bacteria is only under the eyelid. Blinking, tear composition, and lubrication are all part of how the eye functions in relation to this microbiome. While the initial findings and studies were on mice, they were able to confirm similar conditions for human eyes and therefore extend the findings. The one bacterium they’ve identified, genus Corynebacterium, is now being used in colonization studies to further understand this complicated connection between eye microbiome and disease.  In addition, the lab is examining the role of nerves and eye disease. The cornea is the most innervated or densely packed tissue in the body and when it experiences disease, the nerves retract, creating problems for the eye. The lab hopes to better understand the role of these nerves in disease development in hopes of better prevention therapy. For more information and links to Dr. St. Leger’s papers, see his lab’s web page at http://ophthalmology.pitt.edu/people/anthony-st-leger-phd