Are We On The Cusp Of Curing Blindness?
By Kathy Jean Schultz
Following 10 years of painstaking research and preparation, the London Project to Cure Blindness recently announced their first successful surgery on a female patient suffering blindness due to age-related macular degeneration (AMD). Her restored vision will be officially confirmed in a post-operative report sometime this month, but so far her sight remains decidedly restored.
The London Project estimates that macular degeneration accounts for 50% of all visual impairment in the developed world; their mission and dogged trial surgery boasts a new — and highly controversial — treatment that uses stem cells harvested from donated human embryos to reverse AMD.
In other words? We could be on the cusp of curing blindness.
Plant stems spawned the name “stem” cells. Although tiny, a stem holds within it the potential to sprout leaves, branches, flowers, vegetables, fruit, vines, thorns, or huge tree trunks. Likewise, a tiny human stem cell has the capacity to branch out and regenerate damaged cells.
Stem cells have several sources. Some are taken from human embryos. Some, called “cord cells,” come from the umbilical cord, which can be taken just after birth. And still others may be removed from a patient’s own body, often from skin, bone marrow, or the pulpy matter surrounding wisdom teeth. These are called “adult” stem cells, and they need to be processed in a conversion procedure that renders them transplantable. (More on all of this in a minute.)
All this stem cell wizardry isn’t without heated controversy. Opposition in the U.S. centers on taking stem cells from human fetuses, not adult cells. Research funding is steeped in ideological controversy, and government support is limited. Many religious and Right-to-Life groups have worked to prevent federal financing of embryonic stem cell research, with some success.
Stem cells are not without the potential for significant risk, either. One problem is immune system rejection, which happens when the patient’s own system rejects new cells. Another is cancer; transplanted stem cells proliferate quickly. On one hand, this is at the crux of their great advantage in energizing vision restoration; on the other, multiplying rapidly is exactly what cancer cells do. In some cases, converted adult cells have become cancerous. The reason is not yet fully understood.
Doug Oliver, of Nashville, Tennessee, 53, underwent stem cell surgery in August 2015; he had lost much of his sight due to hereditary illness. Using stem cells sourced from Oliver’s own bone marrow, his vision loss was literally reversed following the fledgling procedure. “I went from legally blind to legal-to-drive in eight weeks. I walked around Kroger [grocery store] just so I could read the signs. I wondered what the other shoppers thought of me!”
The Stem Cell Ophthalmology Treatment Study, or SCOTS, is registered as a clinical trial with the U.S. National Institutes of Health. SCOTS — which operated on Oliver — uses adult stem cells sourced from bone marrow, celebrated for its inherently swift replication. While bone marrow’s more familiar purpose is fueling the growth of things like platelets and red blood cells, it’s also, basically, a biological copy/paste button.
“Bone marrow is the most actively dividing cell in the body,” director Dr. Steven Levy explains. “More than any other tissue, bone marrow has regenerative processes.” In examining patients in the wake of successful clinical trial surgeries, Levy says the restoration of the eyes’ functionality is downright astounding.
“We’ve seen regeneration during exams of the retina. We’ve seen reconstitution of the retina, thickening of the nerve. We see cellular regrowth.” It’s not just a “fix” or even a “cure”; these surgeries are actually reversing detrimental deterioration It’s dangerously close to a fountain of youth.
Taylor Binns, 28, is another nearly-blind patient who underwent the stem-cell fueled surgery, not at SCOTS, but at Toronto Western Hospital. Binns describes the dawning horror that began just eight years ago during his second year of college; his corneas were slowly degenerating and with it came chronic pain, “like being stabbed in the eye.”
As time went on, he lost his ability to play sports and eventually lost sight of even his computer screen. “I did my best to hit my keyboard and hoped I hit the right key.”
Finally, in 2010, Binns found himself basically blind, and decided to undergo stem cell transplantation; his sister — a perfect genetic match — served as the donor. Healthy stem cells sourced from her corneas were implanted into his, led by Dr. Allan Slomovic.
Directly following the surgery, Binns remembers being able to see the eye chart, a welcome apparition after two years of indistinguishable blurs that rendered him unable to read or drive. Binns has not only returned to the rugby field, but donning his glasses, his eyesight is 20/20. “It’s validation for me that everything is normal for me now.”
The Intersection of Stem Cell Research And Poverty
While nearly half of people suffering from vision loss in developed countries trace their deterioration to AMD, there are a wide swathe of individuals in undeveloped rural regions that often face irreversible methanol-induced blindness; this watery, largely colorless liquid is an alcohol (typically used industrially as a solvent, pesticide, and alternative fuel source, according to the CDC) is fraudulently sold as drinkable alcohol — often peddled as beer in fact — in unregulated areas.
Window-washing fluid, which is comprised largely of methanol, is also sometimes illegally added to beverages for sale, as a means to dilute legal liquor. Drinking methanol can cause severe metabolic imbalance — basically shutting down your body’s ability to break things down, which in turn leaves the body unable to fight off its poisonous effects, resulting in blindness.
In a 2015 Journal of Stem Cells report, Dr. Himanshu Bansal, in Rudrapur, India, describes a 22-year-old man permanently blinded in both eyes by methanol poisoning. Again, stem cells were extracted from the patient’s bone marrow and processed to make them suitable for vision treatment, and then transplanted into his eyes. He eventually recovered 20/20 vision.
It seems “permanent blindness” isn’t all that permanent.
The Evolution of Sourcing Stem Cells
The state of the art changes every day. Dr. Dennis Clegg is director of the University of California Santa Barbara’s Center for Stem Cell Biology and Engineering, and Co-director of the California Project to Cure Blindness. “In addition (to the London trial) we are involved in another project funded by the Foundation Fighting Blindness that would be useful to replace both photoreceptors and RPE (retinal pigment epithelium cells),” he wrote in an email. “This project is still in its early days, but we hope to develop it into a therapy for RP/injury.”
Fatima Syed-Picard, of the University of Pittsburgh’s Departments of Ophthalmology and Bioengineering, reported a study where dental stem cells extracted from the pulpy area surrounding adult wisdom teeth were converted into tissue to regenerate corneas. There are practical advantages to using dental cells instead of bone marrow, as they’re less invasive for the patient. A Journal of Natural Science, Biology and Medicine article describes dental cells as “convenient and affordable to collect.”
Wisdom-tooth extraction is already commonplace in developed countries and therefore understood. If not fun or welcome, it’s at least a known entity and procedure; cultural familiarity is often able to blunt the sci-fi scent that hampers other medical advances.
University of Pittsburgh Professor of Ophthalmology, Cell Biology and Physiology, James L. Funderburgh, studies regeneration of the human cornea. Vision loss due to scarring on the cornea affects millions worldwide. One standard treatment is corneal transplant. Transplanted corneas come from recently-deceased anonymous donors. Transplants can be complicated if patients’ own immune systems reject them. Funderburgh looks for alternatives.
Embryonic cells have capabilities over a wide array of diagnoses. Adult cells’ uses are fewer. Embryonic cells can be preserved indefinitely, while adult cells cannot. Funderburgh says, “Human embryonic stem cells offer an important resource as a limitless supply of any differentiated cell type of the human body.”
The Slippery Slope Of Regulations And Funding
While regulations and politics shift from border to border, borders have not stopped scientists worldwide from sharing advances with each other online. In some areas of China, abortion has been state-sponsored due to limits on the number of babies people are permitted to have. In a nation where so many abortions take place, there are more embryonic stem cells available for donation. Opposition to research isn’t very strong, the regulations against it are often unenforceable, and Chinese officials smell profit because the World Health Organization estimates 285 million people are vision-impaired.
Writing in 2014, Interfax’s Shanghai bureau chief Colin Shek observed:
“China’s treatment of abortion may have normalized the practice, paving the way for acceptance of embryonic stem cell research . . . ethical qualms would have taken a back seat to the Chinese government’s desire to move from ‘made in China’ to ‘innovated in China.’ Stem cells fit in with Beijing’s ambitious plans to vault the country to the top of the research ranks.”
While some would have research outlawed, others are racing to support it. In 2011, the London Project found itself in the fast lane with European car-racing companies Storholm Racing and Middle Eastern Motorsports. Racecar drivers from both companies competed in the Intercontinental Le Mans Cup as a lucrative fundraiser for the Project. Crankandpiston.com heralded the event: “What could be more pertinent than all the color, action, and excitement of a famous car race to remind us how lucky we are to have the gift of vision?”
Avoiding controversy often means accepting no government funds. Apart from car-racing, much of the London Project’s funding is spearheaded by pharmaceutical giant Pfizer. UC Santa Barbara’s center was “established free of federal funding to allow research on all stem cell lines,” and draws support from private donors, investors, and the California Institute for Regenerative Medicine (CIRM). As chronicled on CIRM’s blog, The Stem Cellar, one of CIRM’s investors is Google Ventures.
SCOTS trials are patient-funded, meaning patients pay to participate. Patient- funded trials are free from bureaucracy; Doug Oliver raised money for his surgery with a GoFundMe campaign.
And still the controversy rages. Critics argue patient-funded trials by definition exclude those who cannot afford it. Proponents argue patients with resources should be able to spend their money as they wish, and that scientific advances ultimately benefit all segments of society.
Lead Image: Flickr/Angel Ortega