Vision loss affects millions of Americans each day — some experience macular degeneration, glaucoma or even vision impairment from a traumatic brain injury. Although there are some medicines and treatments for vision loss, there is no cure.
That’s why a new multi-institutional project, funded up to $46 million by the Advanced Research Projects Agency for Health (ARPA-H) Transplantation of Human Eye Allografts (THEA) program, part of the U.S. Department of Health and Human Services, aims to develop treatments to restore vision through whole eye transplantation.
The award will support the Total Human Eye-allotransplantation Innovation Advancement (THEIA) project led by the University of Colorado Anschutz Medical Campus. Indiana University School of Medicine is one of eight institutions contributing to this groundbreaking research.
As part of the program, IU School of Medicine’s Jason Meyer, PhD, the A. Donald Merritt Professor of Medical and Molecular Genetics, is studying how using stem cells in a dish might stimulate regrowth of nerve connections between the eye and brain. IU will receive $2.2 million through the award.
Meyer said there has never been a successful whole human eye transplantation that has restored vision. Unlike other organs that can be transplanted and have restored function, Meyer said the optic nerve — the only connection between the eye and the brain that relays visual information — would be severed from the patient before an eye transplantation.
“When you take a donor eye, you need to regrow those connections,” Meyer said. “Regrowth of those neuronal connections between retinal ganglion cells in the retina to visual targets in the brain is very difficult.”
Total eye transplantation could potentially help people with vision loss disorders, such as macular degeneration. The disorder that causes vision loss in the center of the eye affects nearly 20 million people in the United States, especially those over the age of 40.
Meyer, director of the Stem Cell Research Group at Stark Neurosciences Research Institute, and his research team, along with colleagues from the University of Wisconsin and the National Eye Institute, will use human stem cells to develop ways to stimulate optic nerve regeneration and connectivity between the donor eye and the recipient’s optic nerve and brain.
Additionally, researchers from Johns Hopkins University will study how modifying genetics of the retina and optic nerve could encourage regeneration, and researchers from the University of Southern California are studying whether electrical signals could support nerve cell regeneration.
Ultimately, each of these groups are trying to stimulate reconnection of the optic nerve.
“In the dish we can grow induced pluripotent stem cells in virtually unlimited quantities and set them up in in vitro models of the optic nerve, where we can test if we can sever the axons of an optic nerve,” Meyer said. “We’ll try to identify the most promising ways to reconnect the optic nerve between the retinal part of our model and the brain part of our model in the dish.”
Meyer uses pluripotent stem cells, which are human stem cells reprogrammed from human donor cells like skin cells and blood cells, in the lab to study any type of cell in the body. They’ve used this to better understand diseases of the retina, such as macular degeneration and glaucoma, as well as Alzheimer’s disease and other neurodegenerative disorders.
Using the findings from the total eye transplantation investigations, Meyer said he’s hoping to translate them into animal models of optic nerve regeneration and eventually clinical trials.
“This will be a neat new direction for my lab to be involved in something this translational,” Meyer said. “It's also a testament to the strengths of the research programs overall within the IU School of Medicine, particularly in the Stark Neurosciences Research Institute, that we've been able to grow our research here to be such a pivotal player in this broader team.”
