Blinded by the Promise of Stem Cell Treatments

Alan F. Cruess cautions against the use of unproven stem cell ‘treatments.’


Recently, many of you may have read about three patients who are blind after receiving stem cell ‘treatments.’  The patients were ‘treated’ at a Florida clinic for age-related macular degeneration. This common eye condition is the leading cause of vision loss among people over the age of 50. The clinic harvested stem cells from the patients using liposuction and then injected these stem cells into their eyes. Again, these three patients, are now all blind as a result of this unproven ‘treatment.’

There are two types of age-related macular degeneration: ‘wet’ and ‘dry.’ In recent years, treatment of wet macular degeneration has been transformed by new drugs which can be very effective if they are applied early. Meanwhile, treatment of the more common dry macular degeneration remains elusive. As such, patients with dry macular degeneration may be desperate to prevent and reverse blindness and willing to try emerging regenerative therapies.

Some experimental stem cells treatments to prevent blindness are promising, and they are being studied worldwide in laboratories and highly regulated clinical trial settings. In these settings, the safety and efficacy of experimental treatments can be closely monitored. Yet, the safety and efficacy should be called into question when these so-called ‘treatments’ are marketed outside of the research context. This was the case at the Florida clinic.

Before subjecting oneself or a loved one to any new ‘treatment’ with stem cells patients should be informed about the risks and potential benefits of the proposed treatment. Patients and their families should feel free to ask any questions that come to mind regarding the treatment being offered.

Thus far, with few exceptions, stem cell ‘treatments’ have not been accepted into mainstream clinical care. In most cases where there are ongoing clinical trials, much study and follow-up remain to be done before the Food and Drug Administration in the United States and other health regulatory approval is forthcoming.

The International Society for Stem Cell Research has recently released guidelines for clinical translation of stem cell research.  These guidelines highlight the stark difference between innovative treatments that are founded on methodical pre-clinical evidence and rigorous clinical trials, and unproven interventions that are offered by practitioners who are either naïve regarding the biologic complexities of stem cells or are unethically peddling the 21st century equivalent of snake oil.

Although some researchers are hopeful about stem cell-based interventions, the majority of these interventions remain unproven and experimental, except in the context of blood-related and skin conditions. For example, stem cell treatments are an accepted standard of care for blood disorders such as chronic leukemia. Despite this fact, clinics throughout the world offer stem cell interventions for a wide variety of conditions, such as Parkinsonism and diabetes, where there is insufficient proof of effectiveness. In many of these clinics, regulatory oversight is bypassed because the clinics offering the unproven interventions are using the patient’s own cells which have been minimally manipulated. When this is the case, the stringent regulations applied by federal regulators (for example, Health Canada and the Food and Drug Administration in the United States) don’t apply. Meanwhile, anecdotal reports of cures trumping hard clinical trial evidence have allowed a stem cell industry to thrive.

Our first duty as physicians is to do no harm. At the very least this means that we need to acquaint our patients with the risks and potential benefits of interventions they may be contemplating. When asked, we need to review the evidence available regarding specific treatments in question, and to explain our concerns patiently if Health Canada approval is pending or absent. This is especially true for experimental stem cell-based ‘treatments’ that tend to garner lots of media hype.


Alan F. Cruess is a Professor in the Department of Ophthalmology and Visual Sciences at Dalhousie University.

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