London: Scientists claim to have successfully healed the damage caused to glaucoma in rats, a breakthrough they say could lead to an effective treatment for one of the most common causes of blindness in humans in just a few years.
Researchers at University College London who carried out this landmark research hoped that their new stem cell therapy could be tested on humans by 2015 and in widespread use four years later.
Glaucoma affects about 70 million people around the world and one in 10 sufferers go blind because of late diagnosis, drugs not working or the disease being particularly severe at present, a newspaper reported.
In the study, the researchers took healthy stem cells -- "master" cells capable of turning into other types of cell and widely seen as a repair kit for the body -- from human eyes.
Using a cocktail of chemicals, they turned them into retinal ganglion cells that die in glaucoma and then injected those into the eyes of rats with glaucoma-like damage.
After just four weeks, the cells had connected with existing nerve cells, and the animals eyes worked 50 percent better, the researches reported in the journal Stem Cells Translational Medicine.
Study author Dr Astrid Limb said: "Although this research is still a long way from the clinic, it is a significant step towards our ultimate goal of finding a cure for glaucoma and other related conditions.
"The human eye is actually very efficient. We can still have fairly good vision with very few functioning retinal nerve cells, which is why many glaucoma patients don`t show symptoms until it is too late to treat the underlying cause of their vision loss.
"If we can restore even a small number of retinal, ganglion cells through cell therapy, and achieve functioning vision, we could potentially delay or even reverse blindness caused by glaucoma."
However, the researchers cautioned that their work is still at an early stage but even a small improvement on vision could make a big difference to quality of life.
In glaucoma, the build-up of pressure in the fluid in the eye damages cells in optic nerve, which ferries visual information to the brain for processing.
The researcher envisions the setting up of cell banks, similar to those used to store blood.
Other possibilities include to take healthy stem cells from a person’s own eye and developing a drug that triggers the development of replacement cells inside the eye, removing the need for any sort of op.
Study co-author Prof Peng Khaw said that even a small improvement in vision could transform lives.
He added: "Research like this gives hope to the many millions of people who have lost their sight due to glaucoma."
Dr Dolores Conroy, of charity Fight for Sight, which also helped fund the research, said: "Currently, there is no way to restore the vision of the millions of people who have lost their sight through glaucoma.
"This research shows that in the near future, it may be possible to use adult stem cells to preserve and restore sight lost through this devastating eye condition.
"These results bring us another step closer to treating one of the leading causes of sight loss in the UK with stem cell therapy."