The human embryonic stem cells will be used to cure inherited blindness in 12 people for the first time ever.

Stargardt's macular dystrophy is a gene disorder that occurs due to the death of retinal pigment epithelial cells (RPEs) from an early age of 6. Death of RPEs is followed by the death of photoreceptor cells that derive their support and nutrition from RPEs. Blindness ensues from the lack of ability to capture light signals. This condition impairs vision in 1 in 8000 people in the United States. Eye injections of 50,000 and 200,000 RPEs are given to Stargardt's macular dystrophy patients. The Worcester Company Advanced Cell Technology (ACT) at Massachusetts was successful in changing hESCs to RPEs in 2004. Now, they plan to implant new RPEs with the correct gene and prevent or reverse the degeneration. News cells will be injected by a surgical procedure into the space occupied by RPEs, directly adjacent to the photoreceptor cells.

"The goal is to halt the rate of photoreceptor loss". "We will hopefully show safety, and we may be able to see improvements in vision in as little as six months," says Robert Lanza, ACT's chief scientist.

The particular advantage of this procedure is that unlike the previous hESC treatment of spinal cord injuries, it is possible to monitor the fate of the new cells with a microscope. In the event of adverse effects, the new cells can be removed.

"Stargardt's is an ideal indication," says Lanza. "There's a definitive endpoint, for measuring visual acuity."

This news is welcomed by other stem cell researchers. "It's fantastic news that they are going into the clinic with a cell therapy for eye disease," says Dr.Pete Coffey, University College London. Dr. Coffey is a specialist at treating age-related macular degeneration.

In another type of blindness called age-related macular degeneration, aging of RPEs leads to loss of vision. 30 million people are affected by this condition worldwide. ACT is working on getting FDA approval for separate trials on age-related macular degeneration.