The report makes for chilling reading. Three women, all suffering from macular degeneration – the leading cause of vision loss in the US – went to a Florida clinic hoping that a stem cell therapy would save their eyesight. Instead, it caused all three to go blind.

Irreparable harm

The study, in the latest issue of the New England Journal of Medicine, is a warning to all patients about the dangers of getting unproven, unapproved stem cell therapies.

In this case, the clinic took fat and blood from the patient, put the samples through a centrifuge to concentrate the stem cells, mixed them together and then injected them into the back of the woman’s eyes. In each case they injected this mixture into both eyes.

Within days the women, who ranged in age from 72 to 88, began to experience severe side effects including bleeding in the eye, detached retinas, and vision loss. The women got expert treatment at specialist eye centers to try and undo the damage done by the clinic, but it was too late. They are now blind with little hope for regaining their eyesight.

In a news release, Thomas Alibini, one of the lead authors of the study, says clinics like this prey on vulnerable people:

“There’s a lot of hope for stem cells, and these types of clinics appeal to patients desperate for care who hope that stem cells are going to be the answer, but in this case these women participated in a clinical enterprise that was off-the-charts dangerous.”

Warning signs

So what went wrong? The researchers say this clinic’s approach raised a number of “red flags”:

• First, there is almost no evidence that the fat/blood stem cell combination the clinic used could help repair the photoreceptor cells in the eye that macular degeneration attacks.
• The clinic charged the women $5,000 for the procedure. Usually in FDA-approved trials the clinical trial sponsor will cover the cost of the therapy being tested.
• They injected both eyes at the same time. Most clinical trials would only treat one eye at a time and allow up to 30 days between patients to ensure the approach was safe.
• Even though the treatment was listed on the clinicaltrials.gov website, there is no evidence that this was part of a clinical trial, and certainly not one approved by the Food and Drug Administration (FDA), which regulates stem cell therapies.

Clinical trials

As CIRM’s Abla Creasey told the San Francisco Chronicle, there is little evidence that fat‑derived stem cells are effective or safe for eye diseases. “There’s no doubt fat contains stem cells. Whether they are the right cells for the eye is a different question. Using the wrong stem cells in the wrong place will lead to bad outcomes.”

The study notes that not all projects on ClinicalTrials.gov are reviewed to ensure they are scientifically sound or supported by proper preclinical testing.

Jeffrey Goldberg, a Stanford Ophthalmology professor and study co‑author, warned patients about unproven therapies: “Stem cell therapy has strong potential, but there is no excuse for poorly designed trials that lack preclinical evidence.”

Several resources are available for people considering joining a clinical trial, including CIRM’s “So You Want to Participate in a Clinical Trial” and the website A Closer Look at Stem Cells, sponsored by the International Society for Stem Cell Research (ISSCR).

CIRM is funding two clinical trials for vision loss. One supports Mark Humayun’s macular degeneration research, the same disease these women had. The other supports Dr. Henry Klassen’s work on retinitis pigmentosa. Both trials have FDA approval, showing they completed the testing needed to help ensure safety.

We have often criticized the FDA for slow, cumbersome approvals and still advocate for a more efficient process. But this study is a powerful reminder that safeguards are essential. Any therapy tested in people must undergo rigorous preclinical work to reduce patient risk.

These three women paid $5,000 for treatment. The final cost was far greater. We never want to see that happen again.