Tag: Stargardt disease

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Macular Degeneration Treatments

Stem Cells Reported to Improve Vision

Two patients receiving embryonic stem cells for their blinding retinal diseases reported improvement in their vision. The results were released just last week online in the medical journal Lancet.

Each patient received retinal epithelial pigment cells (aka RPE cells) grown from human embryonic stem cells. RPE cells are the faulty cells in macular diseases such as ARMD and Stargardt’s Disease. In healthy patients, these cells are normal and function appropriately.

Dysfunctional, sick or degenerated retinal epithelial cells lead to progressive loss of vision. As the healthy RPE cells begin to dwindle, so does the vision. The RPE cells are a key component to translating light to vision.

Researchers have been hopeful to replace sick RPE cells with the healthy replacements derived from the stem cells.

Hence, the excitement. Two individuals, one with dry ARMD and the other with Stargardt’s underwent RPE cell transplantation and the reports at 4 months after the operation are encouraging. Both noted improvement and, according to the report, no complications occurred either to the eye or to the patient.

Both patients underwent surgery at UCLA. The research was funded by Advanced Cell Technology, the same company conducting stem cell research on patients with Stargardt’s Disease.

What Does This Mean?

At most, this is encouraging news.  This does NOT mean that stem cell transplantation works.

There are lots of flaws; only 2 patients involved, inability to objectively measure improvement in vision, funding company (Advanced Cell Technology) is involved and adds bias to the study results, etc.

On the other hand, I am very excited that the research seems to be moving forward. Yes, the results are tainted, but it does demonstrate several “successes” in solving some of the technical challenges of stem cell research;

  • This is pioneering work. Regardless of visual outcomes, researchers have designed techniques to deliver the RPE cells to the correct anatomic location. That is, retinal surgeons have figured out how to transplant the cells effectively.
  • The cells may indeed remain “alive” when transplanted. How long? We don’t know, but it seems to be at least 4 months!
  • This is great news in the face of recent failures of stem cells used in spinal cord injury.
  • There were apparently no complications.

This certainly is enlightening and exciting.  With time, we will need more extensive research and objective data.  This is no different than a new “drug” fighting for FDA approval.

There is still many questions to answer the ultimate questions;  Is the technique safe?  Is the technique effective?

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Macular Degeneration Treatments

Stem Cells for Stargardt's Macular Dystrophy and Macular Degeneration

RPE Transplantation for Stargardts Disease

 

Advanced Cell Technology recently announced the beginning of their landmark trial where stem cells are transplanted into patients with Stargardt’s Macular Dystrophy (aka Stargardt’s Disease) and dry macular degeneration.

Clinical Trials for Stargardt’s Begin

The company announced that their phase I/II clinical trials started in mid-July with one patient each of either Stargardt’s or macular degeneration.  Each patient received a relatively small dose of cells and subsequent patients will receive larger amounts of cells.  The first patients received about 50,000 cells.

The goal of the study, at this phase, is to test the safety and tolerability of the stem cell treatment over a 12 month period, that is, phase I/II will answer the question as to “how safe is the procedure?” and will also asses if this is a viable way to transplant stem cells.

Retinal RPE Cells are Replaced

The cells to be replaced are called RPE (retinal pigment epithelial) cells and are located underneath the top layer of the retina.  If you liken the retina to be an open faced sandwich with a slice of ham with cheese on top, the RPE cells are the slice of ham.  The “rods and cones” (otherwise known as photoreceptors) are located on the underside of the cheese.  The RPE cells nourish the photorecptors.

In cases of Stargardt’s disease and dry macular degeneration, the faulty RPE cells can no longer nurture, or feed, the photoreceptors, hence, the loss of vision.  It is hoped that by replacing the sick retinal pigment epithielial cells with stem cells, the vision can return.

What Does This Mean? This is really promising and exciting news.  On the horizon is the potential for a true “fix” for two of the most common forms of “blindness” in the world.  Actually, most of these patients are legally blind as you remember that the macula gives us central vision.  Thus, RPE transplantation should improve the central vision.

In my view, there are two large variables or areas of concern.  First, the actual technique of implanting the cells must be refined and perfected and at the same time, we need to see how long the stem cells can live or remain healthy.

While this is very promising, this may still be years away from becoming a viable treatment option.

Here is further information about patient inclusion into the study for either Stargardt’s Macular Dystrophy and dry ARMD.

 

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Macular Degeneration Treatments

Stem Cells Get FDA Nod for Stargardt's Disease

Advanced Cell Technology, Inc., received FDA approval for starting Phase I/II clinical trial to use stem cells for the treatment of Stargardt’s disease.  Stargardt’s disease is an inherited type of macular degeneration affecting individuals at age 10-20.  There is no cure.

Similar to other macular diseases, the photoreceptors, and the layer of cells just beneath, call the retinal pigment epithelium (RPE), become destroyed due to a genetic defect.  Due to the macular involvement, central vision is lost.

Stargardt’s disease is the a common form of “macular degeneration” that afflicts the young.  It is estimated to affect about 30,000 people worldwide.  It shares in common with ARMD (age related macular degeneration) the loss of photoreceptors secondary to RPE damage and degeneration.

Advanced Cell Technology (ACT) claims the ability to generate healthy RPE cells from human embryonic stem cells.  The idea is to replace the genetically diseased RPE cells with healthy replacements.  In theory, the healthy RPE cells should prevent loss of the photoreceptors, thereby preserving vision.

The phase I/II study will involve 12 patients enrolled into several centers across the United States.  The initial experiments will determine if the RPE cells are indeed safe and if they can be tolerated by the human recipients (i.e., does the body reject the new RPE cells?).

What Does This Mean?  Stargardt’s disease has no cure, and therefore, are great subjects to consider for this possible treatment.  In a way, there is nothing to lose.  Stargardt’s patients also have or had vision, that is, they have experience with vision.  We know that these patients have fully developed visual pathways.

While this group is very small in comparison to patients with macular degeneration, the significance this holds for a potential, effective treatment can only be left to our imagination.  Even a small success in this trial is exciting.

The news of this trial is exciting, but remember further testing (clinical trials III and IV) need to be completed.  Also, the techniques for introducing the cells safely underneath the retina need to be accomplished, too.

More later…I hope.

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