A new study was led by a Veterans Affairs and University of Iowa team that concludes an infusion of stem cells could help restore proper drainage for fluid-clogged eyes that are at risk for glaucoma.
The study was led by Dr. Markus Kuehn who, along with his researchers, injected stem cells into the eyes of mice with glaucoma. These injected cells regenerated the tiny patch of tissue known as the trabecular meshwork, which serves as a drain for the eyes to avoid fluid buildup. As fluid accumulates in the eye, the increase in pressure could lead to glaucoma that damages the optic nerve and can result in blindness. The researchers believe that replacement of damaged or lost trabecular meshwork cells with healthy cells can lead to functional restoration following transplantation into those eyes with glaucoma. The results of their findings are reported in the Proceedings of the National Academy of Sciences.
This type of stem cells used, called induced pluripotent stem cells, has a big advantage as they could be created from cells harvested from a patient’s own skin. The ethical quandary of using fetal stem cells could be avoided plus it also will lessen the chance of the patient’s body rejecting the transplanted cells. The team did get the stem cells to grow into cells like those of the trabecular meshwork by culturing them in a solution that was conditioned by actual human trabecular meshwork cells.
It was encouraging to see that the stem cell injection led to a proliferation of new endogenous cells within the trabecular meshwork. The stem cells appeared not only to survive on their own, but caused the body into making more of its own cells within the eyes, resulting in multiplying the therapeutic effect.
After nine weeks following the transplant, they measured the effects in the mice. General lab mice only live two or three years and the nine weeks is roughly equal to about five or six years for humans.
There are about 120,000 Americans that are blind from glaucoma according to the Glaucoma Research Foundation. There is a high risk in African Americans as well as people over 60 and those with diabetes, or with a family history of the disease. Glaucoma is not curable but can be managed to prevent the eventual loss of vision using eye drops or traditional surgery. These findings hold promise for the most common form of glaucoma, known as primary open angle glaucoma, but researchers aren’t sure yet if this is relevant for other forms of the disease.
It is also unknown if the new trabecular meshwork cells generated from the stem cell infusion might eventually succumb to the same disease process that caused the breakdown in the first place that would require retreatment. It is also unclear if an approach requiring multiple treatments over time would be viable and the researchers plan to continue studying this approach.
Dr. Kuehn leads the Glaucoma Cell Biology Laboratory at the University of Iowa Carver College of Medicine and is also an investigator at the Center for the Prevention and Treatment of Visual Loss at the Iowa City VA Health Care System.
– Dr Fredda Branyon