Rats with an eye disease similar to human macular degeneration experienced significantly slower vision loss after receiving embryonic stem cell therapy when compared to rats that did not receive the treatment, say scientists from Advanced Cell Technology, USA. If further studies could lead to an effective treatment for humans millions of people around the world might not go blind. Macular degeneration is the most common cause of blindness for people over 55.

You can read about this study in the journal Cloning and Stem Cells.

When tissue implants were injected into the rats with degenerative eye disease their deterioration of vision was slowed down significantly.

The scientist managed to turn embryonic stem cells into retinal pigment epithelium cells. These cells feed the photoreceptor eye cells (light-sensitive cells in the eyes). These cells were injected into 14 rats with degenerative eye disease, while another 8 rats did not receive the injection.

The researchers found that the treated rats achieved a visual acuity of about 70%. After 40 days the treated rats were twice as responsive to flashes of light as the untreated ones.

Retinal examinations showed that while the treated rats’ photoreceptor layers were 5-7 cells thick, the untreated ones’ were just 1 cell thick.

Team leader, Robert Lanza, said “Embryonic stem cells promise to provide a well-characterised and reproducible source of replacement cells for clinical studies. All 18 human embryonic stem cell lines we studied reliably produced retinal cells that could potentially be used to treat retinal degenerative diseases, such as macular degeneration. We showed that these cells have the capacity to rescue visual function in animals that otherwise would have gone blind. Importantly, the cells did not appear to cause any unwanted pathological responses in the animals following transplantation.”

Human Embryonic Stem Cell-Derived Cells Rescue Visual Function in Dystrophic RCS Rats
CLONING AND STEM CELLS Volume 8, Number 3, 2006 ? Mary Ann Liebert, Inc.
Raymond D. Lund, Shaomei Wang, Irina Klimanskaya, Toby Holmes, Rebeca Ramos-Kelsey,Bin Lu, Sergej Girman, N. Bischoff, Yves Sauv?, and Robert Lanza
Click Here To Download The Report (PDF)

Written by: Christian Nordqvist
Editor: Medical News Today