Scientists are working on eye transplants for vision loss. Who will sign up?
Awash in a fluid finely calibrated to keep it alive, a human eye rests inside a transparent cubic device. This ECaBox, or Eyes in a Care Box, is a one-of-a-kind system built by scientists at Barcelona’s Centre for Genomic Regulation (CRG). Their goal is to preserve human eyes for transplantation and related research.
In recent years, scientists have learned to transplant delicate organs such as the liver, lungs or pancreas, but eyes are another story. Even when preserved at the average transplant temperature of 4 Centigrade, they last for 48 hours max. That's one explanation for why transplanting the whole eye isn’t possible—only the cornea, the dome-shaped, outer layer of the eye, can withstand the procedure. The retina, the layer at the back of the eyeball that turns light into electrical signals, which the brain converts into images, is extremely difficult to transplant because it's packed with nerve tissue and blood vessels.
These challenges also make it tough to research transplantation. “This greatly limits their use for experiments, particularly when it comes to the effectiveness of new drugs and treatments,” said Maria Pia Cosma, a biologist at Barcelona’s Centre for Genomic Regulation (CRG), whose team is working on the ECaBox.
Eye transplants are desperately needed, but they're nowhere in sight. About 12.7 million people worldwide need a corneal transplant, which means that only one in 70 people who require them, get them. The gaps are international. Eye banks in the United Kingdom are around 20 percent below the level needed to supply hospitals, while Indian eye banks, which need at least 250,000 corneas per year, collect only around 45 to 50 thousand donor corneas (and of those 60 to 70 percent are successfully transplanted).
As for retinas, it's impossible currently to put one into the eye of another person. Artificial devices can be implanted to restore the sight of patients suffering from severe retinal diseases, but the number of people around the world with such “bionic eyes” is less than 600, while in America alone 11 million people have some type of retinal disease leading to severe vision loss. Add to this an increasingly aging population, commonly facing various vision impairments, and you have a recipe for heavy burdens on individuals, the economy and society. In the U.S. alone, the total annual economic impact of vision problems was $51.4 billion in 2017.
Even if you try growing tissues in the petri dish route into organoids mimicking the function of the human eye, you will not get the physiological complexity of the structure and metabolism of the real thing, according to Cosma. She is a member of a scientific consortium that includes researchers from major institutions from Spain, the U.K., Portugal, Italy and Israel. The consortium has received about $3.8 million from the European Union to pursue innovative eye research. Her team’s goal is to give hope to at least 2.2 billion people across the world afflicted with a vision impairment and 33 million who go through life with avoidable blindness.
Their method? Resuscitating cadaveric eyes for at least a month.
If we succeed, it will be the first intact human model of the eye capable of exploring and analyzing regenerative processes ex vivo. -- Maria Pia Cosma.
“We proposed to resuscitate eyes, that is to restore the global physiology and function of human explanted tissues,” Cosma said, referring to living tissues extracted from the eye and placed in a medium for culture. Their ECaBox is an ex vivo biological system, in which eyes taken from dead donors are placed in an artificial environment, designed to preserve the eye’s temperature and pH levels, deter blood clots, and remove the metabolic waste and toxins that would otherwise spell their demise.
Scientists work on resuscitating eyes in the lab of Maria Pia Cosma.
Courtesy of Maria Pia Cosma.
“One of the great challenges is the passage of the blood in the capillary branches of the eye, what we call long-term perfusion,” Cosma said. Capillaries are an intricate network of very thin blood vessels that transport blood, nutrients and oxygen to cells in the body’s organs and systems. To maintain the garland-shaped structure of this network, sufficient amounts of oxygen and nutrients must be provided through the eye circulation and microcirculation. “Our ambition is to combine perfusion of the vessels with artificial blood," along with using a synthetic form of vitreous, or the gel-like fluid that lets in light and supports the the eye's round shape, Cosma said.
The scientists use this novel setup with the eye submersed in its medium to keep the organ viable, so they can test retinal function. “If we succeed, we will ensure full functionality of a human organ ex vivo. It will be the first intact human model of the eye capable of exploring and analyzing regenerative processes ex vivo,” Cosma added.
A rapidly developing field of regenerative medicine aims to stimulate the body's natural healing processes and restore or replace damaged tissues and organs. But for people with retinal diseases, regenerative medicine progress has been painfully slow. “Experiments on rodents show progress, but the risks for humans are unacceptable,” Cosma said.
The ECaBox could boost progress with regenerative medicine for people with retinal diseases, which has been painfully slow because human experiments involving their eyes are too risky. “We will test emerging treatments while reducing animal research, and greatly accelerate the discovery and preclinical research phase of new possible treatments for vision loss at significantly reduced costs,” Cosma explained. Much less time and money would be wasted during the drug discovery process. Their work may even make it possible to transplant the entire eyeball for those who need it.
“It is a very exciting project,” said Sanjay Sharma, a professor of ophthalmology and epidemiology at Queen's University, in Kingston, Canada. “The ability to explore and monitor regenerative interventions will increasingly be of importance as we develop therapies that can regenerate ocular tissues, including the retina.”
Seemingly, there's no sacred religious text or a holy book prohibiting the practice of eye donation.
But is the world ready for eye transplants? “People are a bit weird or very emotional about donating their eyes as compared to other organs,” Cosma said. And much can be said about the problem of eye donor shortage. Concerns include disfigurement and healthcare professionals’ fear that the conversation about eye donation will upset the departed person’s relatives because of cultural or religious considerations. As just one example, Sharma noted the paucity of eye donations in his home country, Canada.
Yet, experts like Sharma stress the importance of these donations for both the recipients and their family members. “It allows them some psychological benefit in a very difficult time,” he said. So why are global eye banks suffering? Is it because the eyes are the windows to the soul?
Seemingly, there's no sacred religious text or a holy book prohibiting the practice of eye donation. In fact, most major religions of the world permit and support organ transplantation and donation, and by extension eye donation, because they unequivocally see it as an “act of neighborly love and charity.” In Hinduism, the concept of eye donation aligns with the Hindu principle of daan or selfless giving, where individuals donate their organs or body after death to benefit others and contribute to society. In Islam, eye donation is a form of sadaqah jariyah, a perpetual charity, as it can continue to benefit others even after the donor's death.
Meanwhile, Buddhist masters teach that donating an organ gives another person the chance to live longer and practice dharma, the universal law and order, more meaningfully; they also dismiss misunderstandings of the type “if you donate an eye, you’ll be born without an eye in the next birth.” And Christian teachings emphasize the values of love, compassion, and selflessness, all compatible with organ donation, eye donation notwithstanding; besides, those that will have a house in heaven, will get a whole new body without imperfections and limitations.
The explanation for people’s resistance may lie in what Deepak Sarma, a professor of Indian religions and philosophy at Case Western Reserve University in Cleveland, calls “street interpretation” of religious or spiritual dogmas. Consider the mechanism of karma, which is about the causal relation between previous and current actions. “Maybe some Hindus believe there is karma in the eyes and, if the eye gets transplanted into another person, they will have to have that karmic card from now on,” Sarma said. “Even if there is peculiar karma due to an untimely death–which might be interpreted by some as bad karma–then you have the karma of the recipient, which is tremendously good karma, because they have access to these body parts, a tremendous gift,” Sarma said. The overall accumulation is that of good karma: “It’s a beautiful kind of balance,” Sarma said.
For the Jews, Christians, and Muslims who believe in the physical resurrection of the body that will be made new in an afterlife, the already existing body is sacred since it will be the basis of a new refashioned body in an afterlife.---Omar Sultan Haque.
With that said, Sarma believes it is a fallacy to personify or anthropomorphize the eye, which doesn’t have a soul, and stresses that the karma attaches itself to the soul and not the body parts. But for scholars like Omar Sultan Haque—a psychiatrist and social scientist at Harvard Medical School, investigating questions across global health, anthropology, social psychology, and bioethics—the hierarchy of sacredness of body parts is entrenched in human psychology. You cannot equate the pinky toe with the face, he explained.
“The eyes are the window to the soul,” Haque said. “People have a hierarchy of body parts that are considered more sacred or essential to the self or soul, such as the eyes, face, and brain.” In his view, the techno-utopian transhumanist communities (especially those in Silicon Valley) have reduced the totality of a person to a mere material object, a “wet robot” that knows no sacredness or hierarchy of human body parts. “But for the Jews, Christians, and Muslims who believe in the physical resurrection of the body that will be made new in an afterlife, the [already existing] body is sacred since it will be the basis of a new refashioned body in an afterlife,” Haque said. “You cannot treat the body like any old material artifact, or old chair or ragged cloth, just because materialistic, secular ideologies want so,” he continued.
For Cosma and her peers, however, the very definition of what is alive or not is a bit semantic. “As soon as we die, the electrophysiological activity in the eye stops,” she said. “The goal of the project is to restore this activity as soon as possible before the highly complex tissue of the eye starts degrading.” Cosma’s group doesn’t yet know when they will be able to keep the eyes alive and well in the ECaBox, but the consensus is that the sooner the better. Hopefully, the taboos and fears around the eye donations will dissipate around the same time.
Science's dream of creating perfect custom organs on demand as soon as a patient needs one is still a long way off. But tiny versions are already serving as useful research tools and stepping stones toward full-fledged replacements.
Although organoids cannot yet replace kidneys, they are invaluable tools for research.
The Lowdown
Australian researchers have grown hundreds of mini human kidneys in the past few years. Known as organoids, they function much like their full-grown counterparts, minus a few features due to a lack of blood supply.
Cultivated in a petri dish, these kidneys are still a shadow of their human counterparts. They grow no larger than one-sixth of an inch in diameter; fully developed organs are up to five inches in length. They contain no more than a few dozen nephrons, the kidney's individual blood-filtering unit, whereas a fully-grown kidney has about 1 million nephrons. And the dish variety live for just a few weeks.
An organoid kidney created by the Murdoch Children's Institute in Melbourne, Australia.
Photo Credit: Shahnaz Khan.
But Melissa Little, head of the kidney research laboratory at the Murdoch Children's Institute in Melbourne, says these organoids are invaluable tools for research. Although renal failure is rare in children, more than half of those who suffer from such a disorder inherited it.
The mini kidneys enable scientists to better understand the progression of such disorders because they can be grown with a patient's specific genetic condition.
Mature stem cells can be extracted from a patient's blood sample and then reprogrammed to become like embryonic cells, able to turn into any type of cell in the body. It's akin to walking back the clock so that the cells regain unlimited potential for development. (The Japanese scientist who pioneered this technique was awarded the Nobel Prize in 2012.) These "induced pluripotent stem cells" can then be chemically coaxed to grow into mini kidneys that have the patient's genetic disorder.
"The (genetic) defects are quite clear in the organoids, and they can be monitored in the dish," Little says. To date, her research team has created organoids from 20 different stem cell lines.
Medication regimens can also be tested on the organoids, allowing specific tailoring for each patient. For now, such testing remains restricted to mice, but Little says it eventually will be done on human organoids so that the results can more accurately reflect how a given patient will respond to particular drugs.
Next Steps
Although these organoids cannot yet replace kidneys, Little says they may plug a huge gap in renal care by assisting in developing new treatments for chronic conditions. Currently, most patients with a serious kidney disorder see their options narrow to dialysis or organ transplantation. The former not only requires multiple sessions a week, but takes a huge toll on patient health.
Ten percent of older patients on dialysis die every year in the U.S. Aside from the physical trauma of organ transplantation, finding a suitable donor outside of a family member can be difficult.
"This is just another great example of the potential of pluripotent stem cells."
Meanwhile, the ongoing creation of organoids is supplying Little and her colleagues with enough information to create larger and more functional organs in the future. According to Little, researchers in the Netherlands, for example, have found that implanting organoids in mice leads to the creation of vascular growth, a potential pathway toward creating bigger and better kidneys.
And while Little acknowledges that creating a fully-formed custom organ is the ultimate goal, the mini organs are an important bridge step.
"This is just another great example of the potential of pluripotent stem cells, and I am just passionate to see it do some good."
Phil Gutis never had a stellar memory, but when he reached his early 50s, it became a problem he could no longer ignore. He had trouble calculating how much to tip after a meal, finding things he had just put on his desk, and understanding simple driving directions.
From 1998-2017, industry sources reported 146 failed attempts at developing Alzheimer's drugs.
So three years ago, at age 54, he answered an ad for a drug trial seeking people experiencing memory issues. He scored so low in the memory testing he was told something was wrong. M.R.I.s and PET scans confirmed that he had early-onset Alzheimer's disease.
Gutis, who is a former New York Times reporter and American Civil Liberties Union spokesman, felt fortunate to get into an advanced clinical trial of a new treatment for Alzheimer's disease. The drug, called aducanumab, had shown promising results in earlier studies.
Four years of data had found that the drug effectively reduced the burden of protein fragments called beta-amyloids, which destroy connections between nerve cells. Amyloid plaques are found in the brains of patients with Alzheimer's disease and are associated with impairments in thinking and memory.
Gutis eagerly participated in the clinical trial and received 35 monthly infusions. "For the first 20 infusions, I did not know whether I was receiving the drug or the placebo," he says. "During the last 15 months, I received aducanumab. But it really didn't matter if I was receiving the drug or the placebo because on March 21, the trial was stopped because [the drug company] Biogen found that the treatments were ineffective."
The news was devastating to the trial participants, but also to the Alzheimer's research community. Earlier this year, another pharmaceutical company, Roche, announced it was discontinuing two of its Alzheimer's clinical trials. From 1998-2017, industry sources reported 146 failed attempts at developing Alzheimer's drugs. There are five prescription drugs approved to treat its symptoms, but a cure remains elusive. The latest failures have left researchers scratching their heads about how to approach attacking the disease.
The failure of aducanumab was also another setback for the estimated 5.8 million people who have Alzheimer's in the United States. Of these, around 5.6 million are older than 65 and 200,000 suffer from the younger-onset form, including Gutis.
Gutis is understandably distraught about the cancellation of the trial. "I really had hopes it would work. So did all the patients."
While drug companies have failed so far, another group is stepping up to expedite the development of a cure: venture philanthropists.
For now, he is exercising every day to keep his blood flowing, which is supposed to delay the progression of the disease, and trying to eat a low-fat diet. "But I know that none of it will make a difference. Alzheimer's is a progressive disease. There are no treatments to delay it, let alone cure it."
But while drug companies have failed so far, another group is stepping up to expedite the development of a cure: venture philanthropists. These are successful titans of industry and dedicated foundations who are donating large sums of money to fill a much-needed void – funding research to look for new biomarkers.
Biomarkers are neurochemical indicators that can be used to detect the presence of a disease and objectively measure its progression. There are currently no validated biomarkers for Alzheimer's, but researchers are actively studying promising candidates. The hope is that they will find a reliable way to identify the disease even before the symptoms of mental decline show up, so that treatments can be directed at a very early stage.
Howard Fillit, Founding Executive Director and Chief Science Officer of the Alzheimer's Drug Discovery Foundation, says, "We need novel biomarkers to diagnose Alzheimer's disease and related dementias. But pharmaceutical companies don't put money into biomarkers research."
One of the venture philanthropists who has recently stepped up to the task is Bill Gates. In January 2018, he announced his father had Alzheimer's disease in an interview on the Today Show with Maria Shriver, whose father Sargent Shriver, died of Alzheimer's disease in 2011. Gates told Ms. Shriver that he had invested $100 million into Alzheimer's research, with $50 million of his donation going to Dementia Discovery Fund, which looks for new cures and treatments.
That August, Gates joined other investors in a new fund called Diagnostics Accelerator. The project aims to supports researchers looking to speed up new ideas for earlier and better diagnosis of the disease.
Gates and other donors committed more than $35 million to help launch it, and this April, Jeff and Mackenzie Bezos joined the coalition, bringing the current program funding to nearly $50 million.
"It makes sense that a challenge this significant would draw the attention of some of the world's leading thinkers."
None of these funders stand to make a profit on their donation, unlike traditional research investments by drug companies. The standard alternatives to such funding have upsides -- and downsides.
As Bill Gates wrote on his blog, "Investments from governments or charitable organizations are fantastic at generating new ideas and cutting-edge research -- but they're not always great at creating usable products, since no one stands to make a profit at the end of the day.
"Venture capital, on the other end of the spectrum, is more likely to develop a test that will reach patients, but its financial model favors projects that will earn big returns for investors. Venture philanthropy splits the difference. It incentivizes a bold, risk-taking approach to research with an end goal of a real product for real patients. If any of the projects backed by Diagnostics Accelerator succeed, our share of the financial windfall goes right back into the fund."
Gutis said he is thankful for any attention given to finding a cure for Alzheimer's.
"Most doctors and scientists will tell you that we're still in the dark ages when it comes to fully understanding how the brain works, let alone figuring out the cause or treatment for Alzheimer's.
"It makes sense that a challenge this significant would draw the attention of some of the world's leading thinkers. I only hope they can be more successful with their entrepreneurial approach to finding a cure than the drug companies have been with their more traditional paths."