STEM CELLS AND EYE DISEASE
David Steenblock, the author of Umbilical Cord Stem Cell Therapy has treated over 50 patients with macular degeneration with stem cells using both autogenic stem cells (from the same person) and Human cord stem cells (from the umbilical cord of a new born). The majority of patients had a marked improvement of vision but Dr. Steenblock did not measure visual parameters (acuity, contrast, visual fields and ocular tomography) in this series of patients. Dr. Steenblock and I will be collaborating on a study to carefully monitor visual parameters to measure the benefit of stem cell therapy
X-Cell Center in Germany has been utilizing stem cell therapy in the treatment of macular degeneration. They are using autogenic stem cells which are then cultured and treated before utilizing the cells. Their preferred method of treatment for macular degeneration is a retrobulbar injection behind the eye (not into the eye). The researchers in Germany fell that this closer proximity to the eye and macular will increase the benefits. Dr Steenblock feels that this is not necessary and IV administration will work just as well. More research needs to be done to compare these methods. I am planing to visit the X-Cell Center in Germany in Sept 2010 to learn more about the German techniques. Just an aside- Dr Rowen’s father had the stem cells administered by IV not retrobulbar injection
Stem Cells to regenerate a mouse retina
The University of Washington scientists have used human embryonic stem cells (from a cell line approved in the United States) in a lab, then added growth factors — proteins that enable cell growth — central to the development of both human and mouse heads as well as a growth factor essential to a frog’s sprouting of large eyes.
Within two weeks — twice as fast as human cell development — the embryonic cells became progenitor (forerunner) cells for retinal cells.
The scientists injected these into a damaged mouse retina, where they developed into cones (the retinal cells responsible for color), rods (the cells that allow night vision), and other cells.
The scientists’ next step will be to measure the nerve reactions within the repaired mouse retinas to see if vision has improved.
Stem Cells in the treatment of corneal disease
If the limbus area of the cornea is injured or damaged, it can reduce the number of proliferating stem cells. If the corneal stem cells are reduced or eliminated, there is a gradual loss of transparency in the cornea and the formation of scar tissue. Cord stem cell treatments that include CD34 cells may be of benefit to some of these conditions.
However, in cases where neovascularization (the formation of new blood vessels) is a part of the pathology, such as macular degeneration and diabetic retinopathy, hyperbaric oxygen treatments may produce better results than stem cells. A lack of oxygen is generally the initial cause of the growth of new blood vessels and oxygen and antioxidant treatments may help repair eye tissue without increasing neovascularization that can interfere with the retinal center visual field.
IV Stem Cells to treat macular disease
Recently catheter surgery was used to place umbilical cord mesenchymal stem cells directly into the blood vessels that feed the macula area of a patient’s eye. A week later, the person was able to see close images again after being blind for several years.
In three cases of children with cortical blindness, treatments outside the United States using umbilical cord derived stem cells with a predominance of CD133+ neural progenitor cells resulted in moderate to significant improvements in vision. For research on vision and stem cell therapy, click here.
Neural and non-neural stem cell sources are able to repair the injured retina
Haynes T, Del Rio-Tsonis K. Retina repair, stem cells and beyond. Curr Neurovasc Res 2004; 1(3): 231-9.
Stem cells from neural and non-neural sources are potential sources to repair the injured retina. Retinal regeneration may also possible by the transdifferentiation of cells such as the Retinal Pigmented Epithelium, the Pigmented Ciliary Margin and Muller glia cells.
Neuroblastic progenitors have the potential to prevent vision loss in RPE dysfunction
Seiler MJ, Aramant RB. Transplantation of neuroblastic progenitor cells as a sheet preserves and restores retinal function. Semin Ophthalmol 2005; 20(1): 31-42.
Diseases affecting the outer retina usually cause retinal pigment epithelium (RPE) dysfunction. If the damaged part can be replaced with neuroblastic progenitors, vision loss may be prevented. In different animal models of retinal degeneration, retinal transplants can morphologically reconstruct a damaged retina and restore visual sensitivity. Retinal transplantation involves rescue of host cones and synaptic connectivity between the transplant and the host retina.
A novel in vitro retinal differentiation model by co-culturing adult human bone marrow stem cells with retinal pigmented epithelium cells
Shih-Hwa Chioua, , Chung-Lan Kao
aDepartment of Ophthalmology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
Human retinal pigment epithelium (HRPE) cells are important in maintaining the normal physiology within the neurosensory retina and photoreceptors. Recently, transplantation of HRPE has become a possible therapeutic approach for retinal degeneration. By negative immunoselection (CD45 and glycophorin A), in this study, we have isolated and cultivated adult human bone marrow stem cells (BMSCs) with multilineage differentiation potential. After a 2- to 4-week culture under chondrogenic, osteogenic, adipogenic, and hepatogenic induction medium, these BMSCs were found to differentiate into cartilage, bone, adipocyte, and hepatocyte-like cells, respectively. We also showed that these BMSCs could differentiate into neural precursor cells (nestin-positive) and mature neurons (MAP-2 and Tuj1-positive) following treatment of neural selection and induction medium for 1 month.
Furthermore, the plasticity of BMSCs was confirmed by initiating their differentiation into retinal cells and photoreceptor lineages by co-culturing with HRPE cells. The latter system provides an ex vivo expansion model of culturing photoreceptors for the treatment of retinal degeneration diseases.