The researchers say the stem cell method they have developed will help to study the underlying mechanism of glaucoma - a leading cause of blindness that is more common in older people.
Retinal ganglion cells (RGCs) are nerve cells that carry visual signals from the eye to the brain.
Glaucoma - where pressure builds up inside the eye - is the most common condition that affects RGCs. If left untreated, it can damage the optic nerve and lead to vision loss and blindness.
The study, from Indiana University-Purdue University Indianapolis (IUPUI), could also help develop new treatments for optic nerve injuries, such as those incurred by soldiers and athletes, says senior author Jason Meyer, assistant professor of biology.
Glaucoma is the second leading cause of blindness worldwide. Everyone is at risk from the eye disease. Although it is more common in older people, babies can have it too, and in the US, around 1 in every 10,000 babies are born with the condition.
Estimates suggest over 3 million Americans have glaucoma, but only half this number know they have it.
In their study, the team took skin cells from patients with an inherited form of glaucoma and healthy volunteers without the disease and genetically reprogrammed them into pluripotent stem cells.
Pluripotent stem cells are cells in an undifferentiated state; they have the potential to become almost any type of cell in the body.
Model for studying underlying mechanism of glaucoma
The researchers then coaxed the induced pluripotent stem cells (iPSCs) to become RGCs. They found the RGCs made from stem cells took on features specific to RGCs, with the ones from the glaucoma patients showing different attributes to the ones from the healthy volunteers.
Fast facts about glaucoma
- Estimates suggest there could be 60 million people worldwide with glaucoma
- More than 120,000 Americans are blind from glaucoma
- Glaucoma vision loss cannot be regained, but with treatment, it is possible to halt further loss.
The study is interesting because skin cells from people with glaucoma are no different to skin cells of people without the disease, notes Prof. Meyer, who adds:
"However, when we turned glaucoma patients' skin cells into stem cells and then into RGCs, the cells became unhealthy and started dying off at a much faster rate than those of healthy individuals."
The team says the method it has developed could serve not only as a tool to model the underlying mechanism of glaucoma, but could also help to discover and test new drugs for the disease.
This is done by adding different compounds to the RGCs generated in culture from the stem cells to see which ones slow down the degeneration process and prevent the cells from dying off.
Prof. Meyer says they have already started studying some promising candidates and suggests, in the future, they may be able to use healthy cells from patients as substitute cells to find a way to replace cells lost to the disease. He concludes:
"Our ability to direct the differentiation of human induced pluripotent stem cells to functional retinal ganglion cells allows for many new and exciting prospects for personalized medicine."
Meanwhile, Medical News Today recently learned how a "smart" contact lens could predict risk of glaucoma progression.