The first clinical trials that examine the use of stem cells to treat two forms of blindness are ready to begin now that patients have been enrolled, a US company announced on Thursday.
A total of twentyfour patients have entered two separate trials at an eye institute in California, said representatives from the Massachusetts-based Advanced Cell Technology.
ACT was cleared by the US Food and Drug Administration several months ago to begin clinical trials of human embryonic stem cells to treat a form of juvenile blindness known as Stargardt’s disease and dry age-related macular degeneration disease.
Now that patients have been enrolled, the trials will begin “in the very near future,” the company told.
The trials aim to check the safety of the treatment before moving on to see whether the therapy can help stop vision loss.
Dry age-related macular degeneration is the most common form of irreversible vision loss in people over age 55.
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.
Stargardt’s disease causes blindness by destroying the pigmented layer of retina, called the retinal pigment epithelium (RPE). After that follows degradation of photoreceptors, which are cells in retina that detect light.
Patients often experience blur vision, difficulty seeing in low light and ultimately most lose their ability to see altogether. This disease can be inherited by a child when two parents carry the gene that causes it.
Treatment process being tested by ACT worked in animals by creating an abundance of new RPE cells, which are the first cells to die off in Stargardt’s and other forms of macular degeneration.
Tests on rats have shown 100 % improvement in visual performance and “near-normal function” was also achieved in mice, both without negative side effects, ACT has said.
Embryonic stem cell research has been a controversial subject ever since the first such stem cells were isolated more than 12 years ago.
Scientists say the cells offer great promise in treating Parkinson’s disease, diabetes and several other diseases especially genetically transmitted ones.