At the University of Wisconsin-Madison, a team of scientists in Dr. David Gamm’s lab are able to grow stem cells into three-dimensional retinas. These newly formed retinas sit in a dish in the lab and even respond to light.
While Gamm and his team know the cells can function properly on their own, they do not yet know if the human body will easily accept its new part. According to Gamm, who is a pediatric ophthalmologist, there is a relatively low risk associated with injecting a blind eye with an experimental treatment. The eyes are a fairly sequestered organ of the body, so any wily stem cells likely would not be able to travel to other parts of the body. As a last resort for a procedure-gone-wrong, the eye can be removed.
There are anywhere between 75 and 100 trillion cells in the human body, according to scientific estimates, but within the field of stem cell therapies, the eyes are taking the leading position before all other cells for research. Many of the human trials today are taking place for treatments of vision disorders. A key advantage of the eye is that doctors can see how the transplanted cells are behaving by dilating the pupils and examining the eyes, rather than having to go through an MRI or a PET scan.
Gamm’s stem cell research could potentially assist in restoring vision for those with two major blinding disorders. Retinitis pigmentosa is a group of genetic disorders that typically presents in childhood and eliminates peripheral and night vision by attacking photoreceptors. Macular degeneration typically begins in old age and wipes out central vision by attacking RPE cells, which then causes photoreceptors to die off as well.
While photoreceptors play a larger hand in vision, RPE cells are vital supporters as they nourish photoreceptors and remove their waste. Several trials in the past have transplanted RPE cells into patients with macular degeneration with apparent success, but Gamm aims to transplant photoreceptors so that patients with either disease have significantly improved vision.
Gamm’s research follows in the footsteps of James Thomson, the father of stem cell research who also made his breakthrough at the University of Wisconsin-Madison. About 20 years ago, Thomson published proof that he had grown human embryonic stem cells, opening doors to an entirely new branch of research and medicine. Gamm hopes to continue this legacy by starting a clinical trial for vision loss in 2021 at the place where it all began, the University of Wisconsin-Madison Hospital.