Eye Diseases

21
Mar 2017
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BBC program raises concerns over potential dangers of unproven eye treatments

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Last week we wrote about three women whose vision was lost or damaged after they were injected with stem cells derived from their own fat tissue in a Florida clinic.…

Last week we wrote about three women whose vision was lost or damaged after they were injected with stem cells derived from their own fat tissue in a Florida clinic.

This week, a Calgary doctor who uses our website “to educate patients on avoiding the ‘pop up’ shops” offering unproven stem cell treatments, wrote to make us aware of a BBC podcast called  Assignment that recently featured an episode titled The Stem Cell Hard Sell.

The UK program focused on another Florida clinic that provides — for a $20,000 fee — eye implants derived from bone marrow stem cells drawn from a patient’s pelvis.  Central to the piece is the story of an American man named George Gibson who claims he lost sight in one eye after undergoing the procedure.

The treatment is part of a clinical study that’s listed with the U.S. National Institutes of Health called The Stem Cell Ophthalmology Treatment Study-(SCOTS). However it is unclear if the study is approved by the Food and Drug Administration (FDA).  The BBC program points out that researchers usually do not charge patients for the treatments in a clinical trial or study because the outcomes can’t be guaranteed.  As we have written in this space before, having patients pay for treatments tends to encourage them to “buy into” seeing favourable results that might not truly be there.

Dr. Paul Knoepfler, an American researcher whose lab conducts stem and cancer cell research at the University of California Davis School of Medicine in Sacramento, writes extensively about unproven stem cell treatments. His blog, The Niche, has dealt with SCOTS, drawing comments from one man who claims his vision was significantly improved and from others — including Mr. Gibson — who warn against the treatment.

A press release about the SCOTS trial, says investigators “hope that the treatment will be shown to improve vision in the vast majority of individuals who are enrolled” and mentions that “previous anecdotal experience with eye disease treated with stem cells has been positive.” However a disclaimer states that “no guarantees of specific improvements or visual results are being made” and that “any medical procedure carries risks as well as potential benefits.” The study, to include 300 patients, has published two case studies of patients whose vision improved.

Our Towards Treatment section explains that we currently know of no Health Canada of FDA approved stem cell treatments for eye disease.  Anyone considering such a treatment or participating in a study or trial should consult with their doctors and medical professionals.  As well, the International Society for Stem Cell Research has great information for anyone considering any type of stem cell treatment. You can find it here.

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21
Jul 2016
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Dr. Valerie Wallace (UHN Photo)

Cure for macular degeneration may be years away but scientist sees exciting advances on the horizon

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Dr. Valerie Wallace is realistic about finding cell-based cures for blindness.

“It’s a long road,” says the Dr. Wallace, Chair of the Vision Science Research Program at University Health Network’s Krembil Research Institute in Toronto.…

Dr. Valerie Wallace is realistic about finding cell-based cures for blindness.

“It’s a long road,” says the Dr. Wallace, Chair of the Vision Science Research Program at University Health Network’s Krembil Research Institute in Toronto. “Cell transplantation is tremendously complicated, difficult, and painstaking.”

But she is also optimistic about what the future holds for gaining a better understanding of the underlying causes of macular degeneration, which is triggered by deterioration of the cone photoreceptors (cones) in the centre of the eye that mediate reading and seeing fine detail. (In contrast, rod photoreceptors are concentrated along the edges of the retina to facilitate peripheral vision.)

“We are learning a lot about the biology that underpins photo cones, says Dr. Wallace. “They are a rare cell type and understanding their development has been difficult. Now we have tools to do that. That’s what I’m excited about.”

Her lab has developed a new mouse strain with fluorescently tagged cones to allow the researchers to track the progress of the cells to see if they can rescue visual function when transplanted into blind mice.

“We’re looking directly at this. Can cone cells transplant? Can they rescue vision? And if they can, what stage of cone development is the best for transplantation?”

The work she is doing feeds into a larger team effort dedicated to optimizing how to make photo receptors from human stem cells. What she learns from trying to engraft mouse cells will be applied to people. It also has implications for finding therapies for other neural degenerative diseases, such as Parkinson’s disease, Alzheimer’s and stroke.

“The eye has always been thought of as very different from the brain,” she says, “but it is part of the brain.  Our work on identifying novel approaches to promote the survival of these cells could extend to  promote neuron survival in other parts of the central nervous system.”

And the eye, aside from being the window to the soul, can also be a window into a person’s health. Says Dr. Wallace: “People are now using non-invasive imaging of the eye to look at markers of disease. There is a large study in Alzheimer’s that is imaging the eye to identify people at early stages of the disease. That’s happening more and more. People are appreciating that some aspects of eye health might inform the progression or even the diagnosis of other diseases.”

Dr. Wallace, who calls herself “a developmental biologist at heart,” doesn’t forget who she’s working for: people struggling with vision loss. Her past work with the Foundation Fighting Blindness, which helps fund her research, guarantees that. “I hear a lot about what’s important to patients.”

While progress is taking time, the science is steadily moving forward. “A lot of the things we’re doing now were not even being talked about 10 years ago.”

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14
May 2015
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Vision loss trial cleared in California

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Millions of people in North America live with varying degrees of irreversible vision loss. Some good news is that a novel stem cell therapy for retinitis pigmentosa (RP), an inherited condition that slowly damages the retina and can result in blindness, has been cleared by the U.S.…

Millions of people in North America live with varying degrees of irreversible vision loss. Some good news is that a novel stem cell therapy for retinitis pigmentosa (RP), an inherited condition that slowly damages the retina and can result in blindness, has been cleared by the U.S. Food and Drug Administration (FDA) to start a Phase I clinical trial.

The therapy for RP, which affects 1 in 3500 Canadians, was developed by Dr. Henry Klassen, Associate Professor at the Gavin Herbert Eye Institute, UC Irvine School of Medicine, and will consist of injecting patients with stem cells to help replace the cells destroyed by the disease and to save those cells that are not damaged yet.

The goal of the trial, which will involve up to 16 patients, is to evaluate the safety and identify side effects of the treatment. Although it is early to speak about a cure for RP, the researchers are hopeful.

“This milestone is a very important one for our project. It signals a turning point, marking the beginning of the clinical phase of development, and we are all very excited about this project.” said Dr. Klassen in the CIRM press release.

The trial has received almost $20 million in funds from the California Institute for Regenerative Medicine (CIRM).

“One of the goals of the agency is to provide the support that promising therapies need to progress and ultimately to get into clinical trials in patients. RP affects about 1.5 million people worldwide and is the leading cause of inherited blindness in the developed world. Having an effective treatment for it would transform people’s lives in extraordinary ways.” Jonathan Thomas, Ph.D., J.D., Chair of the Governing Board of the CIRM, said in the CIRM press release.

Click here to discover more about how stem cells are being used to understand and treat eye diseases on our Toward Treatments page.

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07
Apr 2015
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Dr. Molly Shoichet

Dr. Molly Shoichet and the future of regenerative medicine

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A few weeks ago, the University of Toronto’s Dr. Molly Shoichet was named as one of five recipients of the L’Oreal/UNESCO Women in Science Award.…

A few weeks ago, the University of Toronto’s Dr. Molly Shoichet was named as one of five recipients of the L’Oreal/UNESCO Women in Science Award.

Dr. Shoichet, the first Canadian to claim the prize since 2009, was recognized “for the development of new materials to regenerate damaged nerve tissue and for a new method that can deliver drugs directly to the spinal cord and brain.”

Dr. Shoichet, whose work is mainly focused on drug delivery and stem cell transplantation strategies, shares her excitement about stem cells and the field of regenerative medicine in a video interview with the Centre for Commercialization of Regenerative Medicine (CCRM).

“There is so much on the horizon of regenerative medicine that is exciting,” says Dr. Shoichet. “Our lab is really focused on the central nervous system, because there is really nothing apart from rehabilitation for these traumatic diseases like stroke, spinal cord injury and even blindness.”

You can view the other installments in the Regenerative Medicine Leadership Series here.

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17
Nov 2014
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Tricky science made simple, part V

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Recently, we posted about the release of another StemCellShorts video: “What is a retinal stem cell?” narrated by Dr. Derek van der Kooy.…

Recently, we posted about the release of another StemCellShorts video: “What is a retinal stem cell?” narrated by Dr. Derek van der Kooy. Stem Cell Shorts is a series of short informative videos produced by Ben Paylor, a PhD candidate at the University of British Columbia, and Dr. Mike Long, a post-doctoral fellow at the University of Toronto.

Dr. van der Kooy, professor in the Department of Medical Genetics and Microbiology at the University of Toronto, who discovered retinal stem cells in 2000 narrates the video.

Dr. van der Kooy and his team have been able to transplant retinal stem cells into the eyes of visually impaired mice and have shown that the tissue regenerated to develop better sight in the animals. Dr. van der Kooy’s hope is to treat degenerative eye diseases such as macular degeneration and retinitis pigmentosa in the next ten years.

The new video is co-sponsored by the Canadian Stem Cell Foundation and the Stem Cell Network.

All the videos — including “What is a stem cell?” narrated by Dr. Jim Till, “What are embryonic stem cells?” voiced by Dr. Janet Rossant, “What are induced pluripotent stem cells?” narrated by Dr. Mick Bhatia, “What is stem cell tourism?” voiced by Prof. Timothy Caulfield, “What is a cancer stem cell?” narrated by Dr. John Dick and “What is a retinal stem cell?” – are now available on the Foundation’s You Tube channel. Click here to view them.

Two final instalments of the series, “What is a blood stem cell?” narrated by Dr. Connie Eaves and “What is a neural stem cell?” narrated by Dr. Sam Weiss are currently in production.

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23
Jul 2014
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Hope, time and (good) practice

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An editorial in the June 11th edition of Nature does two things remarkably well: it offers hope for the future of stem cell science while explaining why it takes so long to get things right.…

An editorial in the June 11th edition of Nature does two things remarkably well: it offers hope for the future of stem cell science while explaining why it takes so long to get things right.

Headlined “Good practice” the Nature piece explains why: “… shortcuts are simply not possible, despite charlatan claims. It takes time to learn how to coax stem cells — either from human embryos or from reprogrammed adult cells known as induced pluripotent stem (iPS) cells — to develop into the right sort of replacement cell. It also takes time to work out how to get these cells to integrate into the host tissue and to function. And the steps required to work out how many replacement cells need to be delivered, and how to deliver them safely, cannot be rushed …”

The editorial urges patience as the field “inches towards clinical testing” and points to two recent developments that inspire considerable optimism.

One is the commencement of clinical trials to treat macular degeneration using retinal stem cells (covered in previous posts here).

The other is the resumption of a clinical trial to test whether embryonic stem cells can help regrow nerves damaged by spinal cord injury. The original trial was halted in 2011 when Geron, the company behind it, decided to use its limited resources elsewhere. Now Asterias Biotherapeutics, buoyed by a $14.3-million grant from the California Institute for Regenerative Medicine, is picking up where Geron left off. (Nature doesn’t mention a Canadian led spinal cord study, but you can read about it here.)

As the article points out, the eye and the spine, in terms of stem cell research, present somewhat easier paths to the clinic: both are isolated, closed systems. The brain and heart, however, are far more complicated. Developing new, stem cell-derived treatments for diseases like Alzheimer’s and Parkinson’s and for cardiovascular conditions will be far more complicated. But there is reason for hope: “Happily, clinical trials are on the horizon. Treatments for Parkinson’s disease are just a few years away from clinical testing. And some for Huntington’s disease may not be far behind.”

One of the reasons things have taken so long is the relative newness of the field: the discovery of embryonic stem cells, which triggered much of the explosion of research underway today, was just 16 years ago. Getting scientists to agree on standardized processes and protocols has taken time. The editorial points to early-days clinical trials for Parkinson’s that didn’t use standardized practices, leading to varying results that were an “uninterpretable mishmash.”

The editorial praises Parkinson’s Disease Global Force, which is bringing together research teams from Europe, the United States and Japan to define standards for cell preparation and patient selection and monitoring for future trials. The scientists will share their universally applicable results, which in turn will move the science forward toward finding treatments and cures.

In short, there will be more trials, fewer errors. And, in the not-too-distant future, new treatments.

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02
Apr 2014
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taylor and slomovic1

Stem cell transplant MD named one of Toronto’s best

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Toronto Life has profiled 30 of “Toronto’s Best Doctors,” with about 1,000 of the city’s physicians participating in a poll to nominate the best MDs based on skills, reputation and their contributions to their field of specialty.…

Toronto Life has profiled 30 of “Toronto’s Best Doctors,” with about 1,000 of the city’s physicians participating in a poll to nominate the best MDs based on skills, reputation and their contributions to their field of specialty.

Dr. Allan R. Slomovic, the Research Director of the Cornea/External Disease Service at the Toronto Western Hospital, University Health Network (UHN), has been profiled as a top eye surgeon.

We recently featured the story of Taylor Binns, who suffered from limbal stem cell deficiency, a rare condition that occurs when the stem cells in a narrow band of tissue around the cornea break down, causing blindness and extreme pain. Dr. Slomovic performed first stem cell transplant in Canada to treat the condition and Taylor is now free of pain and back to his normal life.

Dr. Slomovic has done about eight limbal stem cell transplants in the last two years and is hoping to make UHN the leader in the field of ocular regenerative program.

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21
Feb 2014
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The world is no longer a dark and painful place

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Taylor Binns’ transformation from blindness to “as close to 20/20 as can be with corrective lenses” may seem like story book stuff, but more than three years after his limbal stem cell transplant, he continues to write new chapters.…

Taylor Binns’ transformation from blindness to “as close to 20/20 as can be with corrective lenses” may seem like story book stuff, but more than three years after his limbal stem cell transplant, he continues to write new chapters.

“I am working for a consulting firm, but I am also in a process of getting into medical school,” says the 26-year-old. “The hope is that within a year-and-a-half I will be in medical school somewhere.”

He is also back on the road, driving a car. Back playing his beloved sport of rugby.  And free of the piercing pain that staggered him for almost four years while he was working on his commerce degree at Queen’s University in Kingston.

“It was excruciating,” says Taylor, who grew up in Orillia, Ontario. “Imagine the worst time you ever had with something in your eye. And there was a constant burning sensation.”

Limbal stem cell deficiency (LSCD), a rare condition that occurs when the stem cells in a narrow band of tissue around the cornea break down, produced Taylor’s blindness and eye agony.  Common causes are chemical damage or burns, but sometimes the condition is congenital.  Contact lenses, which Taylor wore, have also been implicated.

As the video above dramatically shows, it was limbal stem cells harvested from his sister Tori that returned Taylor’s sight and banished his pain. Beyond undergoing the procedure, donating her cells posed no problems for Tori. “She’s doing great,” says Taylor. “She’s living in Vancouver where she does hair and makeup for movies and TV shows.”

Taylor, whose LSCD struck during a summer volunteer work stint in Haiti, can’t say enough about Dr Allan R. Slomovic, who performed his four operations at Toronto Western Hospital, beginning in November of 2010. “I was sent to see many doctors around North America and there is no one I would recommend more than him. Professionally and personally, he’s the best.”

Dr. Slomovic, who has done about eight limbal stem cell transplants in the last two years,   says the success rate has been good.  “But not everyone’s like Taylor. He was very fortunate: when we removed the scar tissue from his cornea, the underlying cornea itself was healthy.”

Dr. Slomovic credits Dr. Edward Cole and the staff at University Health Network’s Renal Transplant Program for making limbal stem cell transplants such a success. Their experience in arranging living and deceased donor kidney transplants gives them the expertise to ensure the most compatible donor is found and that the recipient is put on the most appropriate immunosuppression regime after receiving the donated cells.  “It’s a team effort,” says Dr. Slomovic.

As for Taylor, the world is no longer a dark and painful place.  His checkups are down to one every six months. Other than “a little bit” of immunosuppressant drugs, he is no longer on medication.

(For more on stem cells and eye diseases click here.)

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06
Sep 2013
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Scientists focus on curing blindness

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Want to see the future of stem cell science?  Look in the mirror.

See the retina – the thin black line outside the iris?…

Want to see the future of stem cell science?  Look in the mirror.

See the retina – the thin black line outside the iris? Those are retinal pigment epithelial (RPE) cells.  And that’s where the stem cell revolution in new treatments likely will begin.

Outstanding advances in treating leukemia, multiple myeloma and other blood-borne cancers notwithstanding, stem cells have yet to deliver the kind of treatments and cures many had hoped would be available by now. That is soon to change. Not in the blink of an eye, but certainly over the next few years.

“I think that blindness is going to be the first disease cured using pluripotent cells,” says Dr. Derek van der Kooy of the University of Toronto.

Dr. van der Kooy, whose team discovered retinal stem cells 13 years ago, bases his prediction on the fact that the retina is an easy target.

“It’s well laminated and there is this fantastic sub retinal space where you can inject the cells perfectly, exactly where they are supposed to go,” says Dr. van der Kooy. “You can actually see what you’re doing – you can look in the eye and see where you’re injecting the cells. With the heart or the brain, you can’t see where they (the stem-cell-derived transplant cells) are going. Also, it’s an incredibly sensitive assay to see whether they work or not: you can see whether vision improves.”

Dr. van der Kooy’s comments come in the wake of Japan’s announcement that it has approved the world’s first human tests using induced pluripotent stem (iPS) cells. They will be used to produce RPE cells to treat age-related macular degeneration.

Japan’s Dr. Shinya Yamanaka first demonstrated how to create iPs cells in 2006 (in mice) and 2007 (in humans).  Essentially, he came up with a process to take adult skin cells and induce them into becoming pluripotent (capable of differentiating into any cell the body needs) much like human embryonic stem cells. It was an amazing feat for which he won the 2012 Nobel Prize in Physiology or Medicine.

The discovery of iPS cells created a whole new source of pluripotent stem cells and, perhaps more significantly, got around ethical concerns about destroying embryos left over from in vitro fertilization to create embryonic stem cell lines.

But there was a problem. Dr. Yamanaka‘s original method used viruses in the reprogramming process, creating a risk of causing mutations and triggering disease.  Other researchers, notably Dr. Andras Nagy at the Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital in Toronto, have since devised other, non-viral ways of creating the cells to avoid that risk.

Japan invests $1 billion in iPS cells

Clearly, Japan thinks any risk is now negligible. The Wall Street Journal reported in late June that Japan has committed more than $1 billion over the next 10 years to advance iPS cell research and develop clinical applications. The age-related macular degeneration trial – involving just six patients – represents, the WSJ reports, “a big step forward [for Japan] in the race to develop stem-cell therapies.”

Dr. van der Kooy, however, points out that an American company, Advanced Cell Technologies, is already conducting clinical trials to test the safety of RPE cells derived from embryonic stem cells as a therapy for age-related macular degeneration and Stargardt disease (a juvenile form of the condition).

“It is the very first time that people have used iPS cells to try to treat a disease in humans, but conceptually it’s not that different than the ACT trial going on in the States right now,” says Dr van der Kooy. “And there are two other embryonic-stem-cell-derived trials that are going to start: another one in California and one in England. All four will be essentially the same type of trial – attempts to make RPE cells from pluripotent human cells for either macular degeneration or Stargardt’s.”

There is also a potentially crucial Canadian connection to this story.  Dr. Molly Shoichet, a bioengineer and colleague of Dr. van der Kooy at the University of Toronto, has developed a stem cell delivery system that uses a minimally invasive and biodegradable gel called HAMC (pronounced “hammock”) to deliver the progenitor cells to the retina.

“We’ve seen a pro-survival effect in the lab tests and in animal models,” says Dr. Shoichet. “The cells survive better when we deliver them with the gel and they integrate better in the retina.”

So the race is on to cure blindness caused by macular degeneration using with iPS cells and embryonic stem cells. “When you think about it, it’s the general argument for stem cell biology,” says Dr. van der Kooy. “Once cells have degenerated, the only way you’re going to improve them is replace the cells you’re missing.”

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