Glaucoma has been a bit of a mystery for eye professionals and researchers. According to the Glaucoma Research Foundation, an estimated 3 million Americans suffer from the eye disease.
To date, scientists have known little about glaucoma’s cause. Large studies have shown that elevated eye pressure is a major risk factor for the condition, says the National Eye Institute.
However, even that information has confused professionals.
That’s why researchers from the Massachusetts Institute of Technology and Massachusetts Eye and Ear decided to dive into this topic.
According to their study, elevated eye pressure has proven to be an inconsistent risk for glaucoma.
Some people who don’t have the elevated pressure still go onto develop the disease, called low-tension or normal-tension glaucoma.
Even more confusing, glaucoma patients who have received treatments to normalize their eye pressure often still develop vision problems.
According to the study’s authors, that fact alerted them that glaucoma must have a different cause outside of eye pressure.
The Missing Link to Glaucoma
The conflicting information about eye pressure makes sense in light of the researchers’ new discovery.
During their study, researchers found that increased eye pressure invoked an immune response in the eye.
Sound like a wild discovery?
It is because the human eye contains a blood-retinal barrier similar to the blood-brain barrier. This barrier protects the eye, including from the body’s own immune cells.
However, researchers found that as eye pressure rose, the immune system’s T cells were able to infiltrate the eye.
Specifically, these T cells were found to attack stress proteins called heat shock proteins, says Massachusetts Eye and Ear.
Researchers first observed that response in mouse models in which the mice had glaucoma.
However, the mice differed in that some only showcased T cells, some only B cells, and others had neither T nor B cells.
Only the mice with the immune system’s T cells developed vision loss, reports Massachusetts Eye and Ear.
This result confirms a relationship between these immune cells and permanent vision loss.
Associate professor of ophthalmology and co-senior study author Dong Feng Chen, M.D., Ph.D. said that information gives new “hope for finding a cure for glaucoma.”
Chen believes that one day people may even be able to prevent glaucoma from happening at all.
What Causes the Immune Response?
Of course, scientists are still furthering their knowledge about glaucoma’s autoimmune response. According to the study, the authors believe it happens because of a bacterial infection.
The study states evidence in support of this theory, but researchers don’t yet know for sure.
What they have found is that glaucoma patients often showcase more antibodies against a specific type of bacteria.
In addition, the researchers tried to invoke glaucoma in mice raised in bacteria-free environments. Interestingly, they were unsuccessful.
Researchers also saw a similar immune response to the mouse models when they tested several glaucoma patients.
Glaucoma Treatments Need to Improve.
These new findings should help improve current glaucoma treatments.
Often patients find out about their glaucoma when the condition is more severe.
They may already be experiencing blurriness, halos, and blind spots which eventually lead to reduced peripheral vision.
If left untreated, patients can lose much of their central vision too.
Currently, most treatments focus on lowering pressure in the eye.
Professionals have believed these treatments to reduce pressure on the optic nerve, the part that transfers visual information to the brain.
Even in normal tension glaucoma, experts thought patients must have optic nerves more sensitive to eye pressure.
While pressure certainly does play a role, the above study’s information may now new direct treatments. These treatments may aim to halt the body’s immune response or rid it of harmful bacteria.
In the past, patients have had to undergo treatments hoping their glaucoma would not progress. In the future, patients may not need to worry about glaucoma at all.