US biotech company Advanced Cell Technology on Monday said that government has cleared to start its second trail using human embryonic stem cells to treat blindness, in older people.
The trial will examine the therapy's ability to safely treat people with a condition known as dry age-related macular degeneration, the most common form of irreversible vision loss in people over age 60.
There is currently no cure for the disease, which affects around 10-15 million Americans and another 10 million people in Europe, the company said.
The Food and Drug Administration cleared the Massachusetts-based company in November to begin a similar trial on patients with a progressive form of juvenile vision loss, known as Stargardt's disease.
"ACT is now the first company to receive FDA clearance for two hESC (human embryonic stem cell) trials, and is now a true translational leader in the field of regenerative medicine," said Gary Rabin, Interim chairman and chief executive.
"It marks a major step forward, not just within the stem cell sector, but, potentially for modern healthcare techniques."
The company hopes to begin the US clinical trials in the coming months, and intends to seek approval for similar trials in Europe. The US and European market for such a treatment amounts to 25 to 30 billion dollars, it said.
ACT's announcement marks the third such trial, after US company Geron broke new ground last year with the first-ever attempt to use embryonic stem cell therapy on a human patient with spinal cord injury.
Embryonic stem cell research has been a controversial field ever since the first such stem cells were isolated more than 12 years ago. Critics oppose the research because it involves the destruction of human embryos.
However scientists say the cells offer great promise in treating Parkinson's disease, diabetes and a variety of other diseases.