Three macular degeneration patients left blind after unproven stem cell treatment
While undergoing treatment in what was described as a clinical trial, three elderly patients with macular degeneration were blinded after being administered a treatment based on autologous adipose tissue.
A case review recently published in The New England Journal of Medicine describes how three elderly patients with macular degeneration were blinded after they were treated at a Florida clinic (FL, USA).
During the treatment, which was described to the patients as a clinical trial, the patients had adipose tissue removed and processed with unnamed enzymes in an effort to obtain stem cells. The cells were mixed with platelet-dense plasma isolated from the patients’ blood and injected into their eyes.
The review is a "call to awareness for patients, physicians and regulatory agencies of the risks of this kind of minimally regulated, patient-funded research," commented Jeffrey Goldberg of Stanford University School of Medicine (CA, USA), co-author of the paper.
Before the surgery, all three patients, who were aged 72–88 years and paid US$5000 for the therapy, had 20/30 to 20/200 vision. Very unusually for a clinical trial, both eyes were treated at the same time, with the entire process lasting less than an hour. Within a week, the patients had suffered a range of side effects, including vision loss, detached retinas and hemorrhage, ultimately leaving them blind.
"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," said Thomas Albini, associate professor of clinical ophthalmology at the University of Miami (FL, USA), where two of the patients were subsequently treated for complications from the treatment.
Albini speculated that substandard stem cell preparation may have caused some of the complications, which could have been due to introduction of a contaminant or the cell wash solution into the eye. The stem cells also could have changed into myofibroblasts, a type of cell associated with scarring, once they were injected into the eye.
However, both Goldberg and Albini agreed there is no evidence that this kind of therapy could have treated the patients’ sight problems even if carried out correctly and only sparse evidence that adipose cells can differentiate into retinal pigment epithelium or photoreceptor cells, which play a critical role in macular degeneration.
The trial listing has now been removed from ClinicalTrials.gov and the clinic is no longer performing these eye injections, although it is still seeing patients.
Sources: Kuriyan AE, Albini TA, Townsend JH et al. Vision Loss after Intravitreal Injection of Autologous “Stem Cells” for AMD. N Engl J Med; 376:1047-1053 (2017); http://med.stanford.edu/news/all-news/2017/03/unproven-stem-cell-therapy-blinds-three-patients-at-florida.html