Ocular Microbiome May Be Dry Eye Culprit

A mix of microbes may help explain why some people develop dry eye disease, new research showed.

This finding suggests that bacteria may cause dry eye and could someday point to new treatments for the condition and related disorders, which affect an estimated 27 million Americans, according to researchers.

Current treatments aim to preserve and enhance tears and tear production to ease the grittiness and itchiness that accompany dry eye disease. 

To examine the role of the ocular microbiome in dry eye disease, scientists in Texas analyzed swab samples from 30 men and women, nine of whom had dry eye.

They found Streptococcus and Pedobacter species were the most common bacteria in healthy eyes.

In people with dry eye, however, more Acinetobacter species were detected.

"We think the metabolites produced by these bacteria are responsible for dry eye conditions," study coauthor Pallavi Sharma said in a news release about the findings. 

Sharma, a graduate student at Stephen F. Austin State University in Nacogdoches, Texas, presented this research last month at the annual meeting of the American Society for Biochemistry and Molecular Biology. The research team was led by Alexandra Van Kley, PhD, a professor of biology at the university.

"Once we understand the eye microbiota properly, it will improve disease diagnosis at an early stage," Van Kley predicted in the news release. "This knowledge can also serve as a catalyst for developing innovative therapies aimed at preventing and treating ocular disease as well as those that affect the central microbiome site: The gut."

Investigators in Australia have conducted similar experiments in patients with meibomian gland dysfunction, a condition marked by underproduction of key oils in the eye.

One group reported in August 2023 the finding of "detectable differences in the bacterial richness, diversity, and community structure of the conjunctiva and eyelid margin between individuals with meibomian gland dysfunction with and without lacrimal dysfunction, as well as to healthy controls."

More research is needed to confirm and understand the findings, though, and "to determine if manipulating the microbiome could be a potential treatment for the condition," they wrote.