Scientists have successfully improved the vision of three legally blind patients, with one having their eyesight restored. All three patients had retinitis pigmentosa, an inherent disease which slowly constricts vision. The disease currently has no cure but a British firm has reported early success with a procedure which helps to repair the damaged retina.
Before the procedure, the patients were legally blind and could only read the largest group of letters on a special eye test chart.
But 18 days after being injected with stem cells, their sight had improved to the point where they could read three letter sizes smaller.
One patient is no longer classified as legally blind and another said she was able to see the food on her plate for the first time in years.
Olav Hellebo, chief executive of UK biotech firm ReNeuron, said the women went from being capable of seeing nine letters on the eye test chart to 29.
People are considered legally blind if they can read less than 36 letters on the 100-letter chart.
Mr Hellebo said: “She said she could now see the food on her plate, which is really motivating for us to hear.”
The two men improved their eyesight from nine to 24 and from 31 to 45.
The treatment for retinitis pigmentosa requires growing billions of progenitor stem cells in a laboratory.
These have the capability to transform themselves into other types of cells depending on where they are located in the body.
One million stem cells are injected into the back of the patient’s eyeball.
Once there, they transform into new light-sensitive cells called rods and cones which replace ones that have been lost prematurely because of genetic flaws.
Olav Hellebo said the tests on the patients had produced “exciting” results.
“We are obviously very excited. We have to bear in mind all the caveats – that these are results in only three patients and it is early days – but the reaction from ophthalmologists has been very encouraging,” Mr Hellebo told the Mail on Sunday.
Development of the technology has been led by experts at ReNeuron in Bridgend, Wales.
A further nine patients will now have the procedure.
Retinitis pigmentosa, which affects around 25,000 people in the UK, is caused by about 100 inherited genetic defects.
The loss of vision can start in childhood, adolescence or adulthood.
It starts with deteriorating night vision and peripheral vision which then narrows and leaves people with only hazy tunnel vision.
Total blindness usually follows.
Tina Houlihan, of the Retina UK charity which supports people with inherited sight loss, said: “These early results are encouraging and will provide hope to those living with retinitis pigmentosa.
“However, while the trial is at this very early stage, with only a very small number of patients involved, we are cautious in our optimism.”
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