To dissuade people from visiting clinics and availing dubious and experimental stem cell therapies, doctors are warning against potential side effects and complications by citing the case of three women, aged between 72 and 88, who were blinded after undergoing treatment.

The three women were seeking medical intervention for macular degeneration, a progressive age-related medical condition affecting the retina that results in blurred vision or loss of vision. The  "devastating outcomes" as a result of their treatment at a clinic in South Florida has been outlined in a paper that documented and published in the New England Journal of Medicine.

All three patients reportedly suffered from complications including detached retinas, hemorrhages and a complete loss of vision.

"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," Thomas Albini, associate professor of clinical ophthalmology at the University of Miami and co-author of the paper said, while adding that the women may never regain their sight, according to CBC.

The paper emphasizes the "need for oversight of such clinics and for the education of patients by physicians and regulatory bodies," as stem cell therapies are becoming more prevalent in clinics across the U.S. New rules that mandate clinics working on stem cell therapies to get official oversight and approval requirements sanctioned by the U.S. Food and Drug Administration (FDA) were only introduced as late as April 2016.

The paper also mentions that the women believed that they were taking part in a clinical trial because they were aware of the clinic’s work on the website run by the U.S. National Library of Medicine. The paper, however, notes that the cost of the treatment —about $5,000 each— should have been an indicator that the treatment was not a government overseen clinical trial, as patients aren’t usually charged fees for legitimate research.

Dr. Jeffrey Goldberg, chair of ophthalmology at the Stanford University School of Medicine and a co-author of the study also added that the information listed on the are not critically analyzed for their scientific content.

"There is a lot of very well-founded evidence for the positive potential of stem therapy for human diseases, but there's no excuse for not designing a trial properly," Goldberg said highlighting the ability of stem cells in restoring vision as demonstrated in few reputable trials.