Up till now, macular degeneration has stubbornly resisted attempts to reverse its inexorable course. Sufferers are routinely told that
nothing can be done and that they should resign themselves to a life restricted by fading central vision and low vision aids.
All that has now changed. Fascinating new research
reported May 4, 2000 at the Annual Meeting of the Association for Research in Vision and Ophthalmology revealed remarkable progress made towards detecting and deploying resting
omnipotent cells in the eye and other tissues.
The hope: to harvest resting omnipotent cells hiding in various sites in your body and inject them into diseased macular sites. These
cells are then woken up, allowing them to grow and replace defective, dying or dead cells with new, vital and healthy ones.
A slew of papers were presented documenting the
discovery of so-called totipotential cells - cells that have the ability to turn themselves into any other specialized cell that they choose to.
Specifically, scientists discussed
the use of neural stem cells that proceed fully developed nerves and brain tissue. They injected these into the space beneath rat retinas and were able to stimulate them to grow into
macular light sensing cells or photoreceptors after stressing these cells by reducing the blood supply to the retina and then increasing it.
Rat visual acuity was not assessed
before or after, so its unclear if these new photoreceptors were able to connect up the rest of the light sensing and transmission system.
However, the demonstration that one can
grow new photoreceptors in the adult eye is quite extraordinary, and was received with great enthusiasm at the conference.
Other scientists injected neural stem cells into the
vitreous, the gel-like substance bathing the retina that fills the globe of the eye and responsible for retaining its normal oval shape. Under controlled circumstances, the neural
stem cells were able to find their way to the retina and change into photoreceptors.
Other researchers demonstrated similar findings using even more primitive omni-potent cells –
those called embryonic stems cells. First, they were cultured into embryonic bodies. These embryonic bodies were then transplanted into the sub-retinal space. Here, under the
influence of retinoic acid (Vitamin A) and intermittent high and low blood flow stimulation they developed into photoreceptors.
What are the implications of this research for
patients with macular degeneration?
First, this work explodes the myth that macular degeneration is irreversible. As the MDF has long held, it clearly is not. These landmark
studies demonstrate that, in adult eyes, one can resurrect vision-related cells like photoreceptors and induce production of critical visual process dependent chemicals such as
rhodopsin.
Second it emphasizes the critical importance of more funding for omni-potent cell related research as the best hope yet for a cure for this disease. The MDF is
redoubling its efforts to fund additional studies to broaden our understanding of these remarkable cells and develop the best ways to accelerate application of this new knowledge for
humans.
You can help us to help you or someone you love by contributing to the MDF Cells for Sight Initiative. Together we can help better fund the existing small group of
researchers, enabling them to accelerate their work and add new talent and resources to the development of human therapies based upon this exciting discovery.
