Of all the eye research developments reported on the VisionAware blog, it is stem cell research for eye disease that generates the most inquiries from our readers. Many readers request information about stem cells, assuming that this is an established and widely-performed treatment for eye disease; others ask for help in finding a doctor who will administer “stem cell treatments.”
In response to these inquiries, my message is always the same: “Although stem cell research for eye disease has produced a small number of interesting results, it is in its very earliest safety-testing stages and must be subjected to additional, longer-term, rigorous study and clinical trials, encompassing many more years of closely monitored research. Success in this area is not a foregone conclusion. At present, stem cell research is fraught with numerous stops and starts, high expectations, and frequent disappointments.”
It’s important to note that even if a clinical trial for eye disease is listed in ClinicalTrials.gov, it does not always mean that the trial has been approved by the United States Food and Drug Administration (FDA) or the National Institutes of Health (NIH). Patients should always consult with their own physicians before seeking to participate in any clinical trial.
Furthermore, if the sponsors of the treatment or trial request payment from the patient to participate, this raises a significant “red flag.” Such a situation is called “pay to participate” and raises a number of profound ethical issues, including the lack of equal opportunity for all to participate, and the risk/benefit ratio of participating in the research.
A recent article on the VisionAware blog, titled Our Readers Want to Know: What Is the Progress of Stem Cell Research for Eye Disease? Answer: It Has a Very Long Way to Go, also addressed a number of safety issues surrounding experimental stem cell trials for age-related macular degeneration (AMD), particularly the risks of tumor formation and potential immune rejection.
More urgently, the New York Times has published a detailed report of three women with AMD who suffered severe, permanent eye damage after stem cells were injected into their eyes in an unproven treatment at U.S. Stem Cell, a private clinic at Sawgrass Medical Center in Sunrise, Florida.
About the Stem Cell/Macular Degeneration Report
The New York Times report is based on Vision Loss after Intravitreal Injection of Autologous “Stem Cells” for AMD, a Brief Report published on March 16, 2017 in the New England Journal of Medicine. The authors are Ajay E. Kuriyan, MD; Thomas A. Albini, MD; Justin H. Townsend, MD; Marianeli Rodriguez, MD, PhD; Hemang K. Pandya, MD; Robert E. Leonard, II, MD; M. Brandon Parrott, MD, PhD; Philip J. Rosenfeld, MD, PhD; Harry W. Flynn, Jr., MD; and Jeffrey L. Goldberg, MD, PhD. The authors represent Bascom Palmer Eye Institute, University of Miami, FL; Center for Sight, Sarasota, FL; Flaum Eye Institute, University of Rochester Medical Center, NY; Dean McGee Eye Institute, University of Oklahoma, Oklahoma City; and Byers Eye Institute, Stanford University, Palo Alto, CA.
First, Some Basic Stem Cell Terminology
Here is a brief explanation of some key terms that are used in many types of stem cell research:
- Autologous: Involving one individual as both donor and recipient
- Immunogenic: Causing, or capable of producing, an immune response.
- Embryonic stem cells (ESCs): Can form any cell type in the body. However, they are in limited supply, and – due to their origins – have ethical issues attached to their use.
- Pluripotent: A stem cell that has the power to develop into any type of bodily cell or tissue (“pluri” = many; “potent” = having power)
- Human pluripotent stem cells (hPSCs): The term includes both human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs)
- Induced pluripotent stem cells (iPSCs): A type of pluripotent stem cell that can be generated or “reprogrammed” directly from adult cells. Induced pluripotent stem cells require viruses to reprogram the cells, which has the potential to cause cancerous tumors.
About the Harmful Stem Cell Treatment
Excerpted from Patients Lose Sight After Stem Cells Are Injected Into Their Eyes, via the New York Times:
Three women suffered severe, permanent eye damage after stem cells were injected into their eyes, in an unproven treatment at a loosely regulated clinic in Florida, doctors reported in an article published Wednesday in the New England Journal of Medicine.
One, 72, went completely blind from the injections, and the others, 78 and 88, lost much of their eyesight. Before the procedure, all had some visual impairment but could see well enough to drive. The cases expose gaps in the ability of government health agencies to protect consumers from unproven treatments offered by entrepreneurs who promote the supposed healing power of stem cells.
The women had macular degeneration, an eye disease that causes vision loss, and they paid $5,000 each to receive stem-cell injections in 2015 at a private clinic in Sunrise, Florida. The clinic was part of a company then called Bioheart, now called U.S. Stem Cell. Staff members there used liposuction to suck fat out of the women’s bellies, and then extracted stem cells from the fat to inject into the women’s eyes.
Two of the eye patients sued the clinic and settled, but it has faced no other penalties. [The clinic stated that] it no longer treats eyes, but continues to treat five to 20 patients a week for other problems like torn knee cartilage and degenerating spinal discs.
All three women found U.S. Stem Cell because it had listed a study on a government website, clinicaltrials.gov — provided by the National Institutes of Health. Two later told doctors they thought they were participating in government-approved research. But no study ever took place, and the proposed study on the site had no government endorsement. Clinical trials do not need government approval to be listed on the website. Legitimate research rarely, if ever, charges patients to participate, scientists say, so the fees should have been a red flag. But many people do not know that.
The women in Florida suffered detached retinas, in which the thin layer of light-sensing cells that send signals to the optic nerve pulls away from the back of the eye — a condition that usually needs prompt surgery to prevent blindness. Doctors who examined the patients said they suspected that the stem cells had grown onto the retina and then contracted, pulling it off the eyeball.
“The really horrible thing about this is that you would never, nobody practicing good medicine would ever do an experimental procedure on a patient on both eyes on the same day,” said Dr. Thomas A. Albini, an author of the article who saw two of the patients, at the Bascom Palmer Eye Institute. Standard practice, he said, is to treat one eye at a time, usually the worse eye first, so that if something goes wrong at least the patient still has one eye left with some vision.
About Clinical Trials
Most clinical trials are designated as Phase 1, 2, or 3, based on the questions the study is seeking to answer:
- In Phase 1 clinical trials, researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe and effective dosage range, and identify possible side effects.
- In Phase 2 clinical trials, the study drug or treatment is given to a larger group of people to determine if it is effective and to further evaluate its safety.
- In Phase 3 studies, the study drug or treatment is given to even larger groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
- In Phase 4 studies, after the United States Food and Drug Administration (FDA) has approved the drug, continuing studies will determine additional information, such as the drug’s risks, side effects, benefits, and optimal use.
More About the Study from the New England Journal of Medicine
Excerpted from the full version of the article, available via subscription only:
We report three cases of vision loss after patients with AMD received bilateral [i.e., in both eyes; in this case, both eyes were injected on the same day] intravitreal injections of autologous adipose tissue–derived stem cells at a stem-cell clinic. [“Autologous adipose tissue-derived” means that staff members at the clinic used liposuction to suck fat out of the women’s bellies, and then extracted stem cells from the fat to inject into the women’s eyes.] After treatment, in June 2015, the patients were referred to two university-based ophthalmology practices.
Patient 1: A 72-year-old woman with a history of [dry] AMD and a best-corrected Snellen visual acuity of 20/60 in the right eye and 20/30 in the left eye underwent bilateral [i.e., both eyes] injection [into the eyes] of autologous adipose tissue–derived stem cells for the treatment of [dry] AMD.
The patient underwent the procedure at a stem-cell clinic that had an institutional review board–approved research trial listed on ClinicalTrials.gov at the time; however, the written information provided to the patient did not mention participation in a clinical trial, review or approval by an institutional review board, or an association with a trial listed on ClinicalTrials.gov.
The patient reported that she had found the stem-cell clinic through its listing on ClinicalTrials.gov. She also reported that she was under the impression that she was participating in a clinical trial and that she had met the criteria of the trial. She paid $5,000 for the bilateral [i.e., both eyes] procedure. The consent form indicated the risk of blindness. The patient presented to the Bascom Palmer Eye Institute in Miami three days after the intravitreal injection.
Patient 2: [Wet] AMD was diagnosed in a 78-year-old woman with a best-corrected Snellen visual acuity of 20/50 in the right eye and 20/100 in the left eye after she received bilateral injections of anti–vascular endothelial growth factor (VEGF) drugs in both eyes over the course of two years and before she received bilateral intravitreal injections [i.e., injected into both eyes] of autologous adipose tissue–derived stem cells at the same stem-cell clinic.
Like Patient 1, she was aware of the clinical trial posted on ClinicalTrials.gov by the stem-cell clinic. She also paid $5,000 for the same procedure that Patient 1 had undergone. Approximately two days after Patient 2 received bilateral intravitreal injections, she presented to both the Bascom Palmer Eye Institute and to the Center for Sight in Sarasota, Florida.
Patient 3: An 88-year-old woman with a visual acuity of 20/40 in the right eye and 20/200 in the left eye had a history of [dry] AMD with bilateral geographic atrophy and a retinal tear treated with cryopexy in the left eye 30 years before she received bilateral intravitreal stem-cell injections, as described in Patients 1 and 2. Patient 3 received injections at the same stem-cell clinic for $5,000. Patient 3 presented one week after the procedure to the Dean McGee Eye Institute, Oklahoma City.
Discussion: Although numerous stem-cell therapies for medical disorders are being investigated at research institutions with appropriate regulatory oversight, many stem-cell clinics are treating patients with little oversight and with no proof of efficacy. A distinction has been made between clinical studies of stem-cell therapies that are founded on solid preclinical research with strong scientific design and programs that lack preclinical research justification. These programs are often funded by patients at nonacademic centers, and they may not receive FDA oversight if these procedures are performed without the filing of an investigational new drug application with the FDA, which requires extensive safety data.
At least one of the patients thought the procedure was performed within the context of a clinical trial. However, the consent forms signed by all three patients do not mention a clinical trial. The patients paid for a procedure that had never been studied in a clinical trial, lacked sufficient safety data, and was performed in both eyes on the same day. Experimental bilateral [eye] injections are both atypical and unsafe.
The need for oversight of such clinics and for the education of patients by physicians and regulatory bodies is paramount to protecting patients while advancing proper research and innovation.
To Our Readers
Please don’t be enticed by unproven treatments, miracle cures, and faulty science. Always consult with your own physician before you enter any kind of clinical trial. Read the latest American Academy of Ophthalmology Statement on Stem Cell Therapy for Treating Eye Disease.