Doris Tyler, a retired elementary school music teacher, had to drop out of her church choir two years ago when she lost her vision. Since she could no longer see the music, she would need to memorize up to eight hymns a week to participate, and at 78, she just doesn’t have that kind of memory anymore, she says.

“The two hardest things are waking up in the morning, opening my eyes and only seeing darkness and knowing that it will be that way until I close them at night,” she says, sobbing. “The other thing is: I can’t see my children and grandchildren. That’s probably the hardest.”

For years, Tyler, of Ocoee, Florida, was slowly going blind from macular degeneration. Overall, she was getting along okay. She couldn’t drive, but she could still read large print, cook, enjoy her music, and spend time with her family. Then a friend gave her a copy of a book called The Stem Cell Revolution by Mark Berman and Elliot Lander, co-founders of the Cell Surgical Network and owners of a California-based stem cell clinic chain, which suggested that her macular degeneration could be cured with stem cell therapy. She decided to try it.

Within a month of paying $8,900 for stem cell therapy in both eyes — a treatment her doctors had promised would, at worst, do nothing — she couldn’t see anything in her left eye. A month later, she lost vision in her right eye too. Now, she sees only darkness.

Whether she was actually blinded by the procedure itself will be decided by a Florida court as Tyler has taken legal action against the clinics and the doctors who treated her.

“Even many physicians are not sophisticated enough to understand that there are many kinds of stem cells.”

But academic stem cell researchers who spoke with Medium say there’s little doubt that hundreds of clinics around the country that are providing so-called stem cell treatments like the one Tyler received are nothing more than a sham. Though there’s technically only one federally approved stem cell treatment (using stem cells from blood or bone marrow), that hasn’t stopped clinics from popping up and offering everything from knee repairs to stroke treatment to erectile dysfunction therapy.

“Snake oil salesmen capitalize on the fact that people see reports on stem cells,” says Sean Morrison, a former president of the International Society for Stem Cell Research, adding that many clinics offer therapies that haven’t been proven to work and, biologically speaking, don’t even make sense. “Even many physicians are not sophisticated enough to understand that there are many kinds of stem cells.”

Stem cells are important in medicine because they have the potential to turn into different types of cells that can help repair damaged tissue and organs. Embryonic stem cells are especially promising because they have the power to transform into any cell in the body. In the U.S. alone, federally funded scientists have spent $1.4 billion studying embryonic stem cells over the last two decades, and there are currently 29 clinical trials of cells derived from embryonic stem cells underway around the world.

As their name suggests, embryonic stem cells can only come from embryos, but scientists have discovered another way to generate similar, multipurpose cells. In 2006, Japanese researcher and Nobel laureate Shinya Yamanaka crafted a relatively simple method for essentially turning back the clock on adult cells, transforming them into so-called induced pluripotent stem cells (iPS cells). These cells are frequently used alongside embryonic stem cells in research.

Another type are called adult stem cells, which are specialized to form cells only in certain tissues. The most widely used adult stem cell is the blood-forming stem cell, which is the active ingredient in bone marrow and umbilical cord blood transplants — the only federally approved stem cell therapy. Replacing diseased blood-forming stem cells with those from a healthy person can effectively cure some types of blood cancer and genetic diseases, though the process is still risky.

Stem cells found in fat are called adipose tissue-derived stem cells and can be readily taken from the body through a procedure like liposuction, which is one of the reasons they are favored by stem cell clinics. Some claim that fat stem cells have the power to regenerate tissue, helping it heal from injury and tamp down on the inflammation that can cause further damage. This has not yet been proven. Only 20 small studies with patients have been completed worldwide (with none in the U.S.) using fat stem cells for a variety of conditions. Stem cells from fat cannot turn into retinal cells or mature cells from most other tissues, though clinics like the one Tyler went to use them in this way. Like other stem cells, fat stem cells can only be used safely and effectively if they are carefully matched to the tissue and disease to be treated, Morrison says.

There’s no doubt that stem cells will one day be effective treatments, but a lot more research has to happen before then, says Paul Knoepfler, a stem cell scientist and professor at the University of California at Davis School of Medicine, acknowledging that it’s frustrating for patients to wait. Right now, he says, the clinics are taking advantage of the public’s lack of understanding.

Asked whether there’s any scientific evidence to support the treatments many stem cell clinics offer today, Knoepfler says, “I can’t really think of anything.”

After deciding she wanted to pursue stem cell therapy to restore her vision, Tyler called one of the Cell Surgical Network clinics in California. When she said she couldn’t afford to travel so far from Florida, she was referred to an affiliated clinic in Georgia. She paid the clinic nearly $9,000 up front. The day of the procedure, a doctor used liposuction to take some fat from her belly. The cells were then spun in a centrifuge — to amplify the fat stem cells, she was told. About 30 minutes later, some of those spun-out cells were injected into her left eye. The next day, Tyler came back, per the doctor’s instructions, and had more of the cells injected into her right eye.

A month later, Tyler couldn’t see anything but darkness out of her left eye. Her local doctor in Florida told her she had a detached retina, and he surgically reattached it. But it wouldn’t stay put. After several more attempts to reattach her retina at stem cell clinics in Atlanta and Miami, Tyler was told that fast-growing scar tissue — likely triggered by the stem cell procedure — was causing her eye to reject the reattachments. Meanwhile, she lost vision in her right eye; several retinal reattachment surgeries on that eye failed, too. “By that time, after six or seven surgeries, I said that’s it, I give up,” Tyler says.

Although stem cell treatments haven’t been federally approved, stem cell clinics claim they are still allowed to operate under doctor discretion. The Cell Surgical Network says its “surgical procedures fall under the category of physician’s practice of medicine, wherein the physician and patient are free to consider their chosen course of treatment.”

The U.S. Food and Drug Administration (FDA) regulates human cells and tissues intended for procedures like implantation, transplantation, or infusion, primarily to prevent the transmission of disease. Among the regulations are that cell products — as the FDA calls them — must not be heavily processed, they must have a localized rather than whole-body effect, and they must perform the same function in the recipient as the donor.

Six months ago, the FDA filed complaints against two large-clinic operators, saying their stem cell therapies violated federal rules and they needed to stop offering the procedures. An FDA spokesperson declined to comment on pending litigation.

Science is an art, and science is a business. Unfortunately, the business aspect can cloud judgment.”

Cell Surgical Network is the focus of one of the complaints, and co-founder Berman says he’s done nothing wrong. It’s the FDA that’s overstepping its bounds by trying to limit his clinics, he says, and the treatments he offers to thousands of patients a year are nearly risk-free, according to him.

“It’s incredibly safe. They’re your own cells,” Berman says. The cells aren’t changed, he says, so they don’t violate the FDA’s standards.

“Why would I do this for eight years if it didn’t work?” the Beverly Hills cosmetic surgeon asks, noting that he has used stem cell therapy to treat his own sciatica and his wife’s hip problems and often provides treatments for free to patients who can’t afford them. After contacting 1,524 people who had received stem cell therapy from one of his clinics, Berman published a paper in 2017 reporting that of the more than 500 respondents, there were “a very low number of reported adverse events” and that many people reported “a reduction in pain ratings after 6 months or more.”

“We don’t take advantage of anybody,” Berman says.

Academic science has also felt the lure of stem cells. In mid-October, Harvard University and its affiliated Brigham and Women’s Hospital called for the retraction of 31 papers written by one of their stem cell scientists due to concerns of “falsified and/or fabricated data.” The researcher, Piero Anversa, who has since left Harvard, argued that the heart has its own stem cells — a controversial theory that nevertheless gained enough support that clinical trials were based on his ideas. On Oct. 29, the National Heart, Lung, and Blood Institute paused an ongoing research trial, saying the retractions by Harvard “raised concerns about the scientific foundations of this trial.”

Other scandals include an Italian surgeon, Paolo Macchiarini, whose work was retracted for scientific misconduct. All the people he treated with an artificial trachea seeded with stem cells died except for one who had to get the implant removed. In 2014, a Japanese stem cell scientist died by suicide after a paper he co-wrote was retracted due to extensive errors and “inexplicable discrepancies.”

“Science is an art, and science is a business. Unfortunately, the business aspect can cloud judgment,” says Tenneille Ludwig, director of the WiCell Stem Cell Bank in Madison, Wisconsin. “It would be unfortunate if people believed that these few cases that come up represent the majority of the work that is being done.”

Tyler says she trusted her doctors at the Stem Cell Center of Georgia, just like she’s trusted doctors for all her other medical problems. They were very clear, she says, that she might not get any benefit from the stem cell therapy she underwent in September 2016. But they never warned her, she says, that the procedure might make her totally blind. If they had, she would never have risked it. (Reached by phone, someone from the clinic declined to comment on Tyler or her case.)

Berman was not directly involved in Tyler’s surgery but said that after hearing about her situation, he immediately stopped his clinics from treating people with macular degeneration in an abundance of caution. But he doesn’t believe the procedure caused her blindness. He thinks it was something else she did around the same time. She disagrees.

Thomas Albini, a Miami ophthalmologist who examined Tyler after she lost her vision, wrote a paper in the New England Journal of Medicine reviewing the cases of three other people who went blind after stem cell procedures. In a sworn affidavit to Tyler’s law firm, Grossman Roth Yaffa Cohen, Albini concluded that the stem cell therapy was likely the cause of Tyler’s blindness and that her doctors had been “negligent” for operating on both eyes so close in time without evidence that the procedure was safe or effective.

Former international stem cell research president Morrison, who is now director of the Children’s Research Institute at the University of Texas Southwestern Medical Center, says the whole treatment is illogical.

“It makes no sense to inject fat cells into somebody’s eye,” he says. “There’s no chance based on what we understand about the biology that someone would benefit from that.”

Researchers are currently testing whether using stem cells that are related to the retina can help people with macular degeneration, but those are very different cell types than the fat cells Tyler was given, Morrison says. And those studies are being conducted slowly and carefully, with research protocols designed to protect patients — and at no charge to them.

“I don’t want anyone else to go through this, so I want the word to get out as many different ways and places as possible,” says Tyler. She says she’s worried about what will happen to her if her husband, Donald, who is 79, can no longer pick out her clothes, clean the house, or help her get around.

“Even though our sons say, ‘Oh mom, you know we’ll take care of you,’ they all work,” she says. “It will take money to find somebody to take care of me.”