New hope of cure for the colour blind
A NEW discovery by genetic scientists could bring a cure for colour blindness and other diseases that can lead to a total loss of sight.
Researchers in the US made the breakthrough after successfully using gene therapy to treat a pair of squirrel monkeys that could not differentiate between red and green.
It could bring new treatments for a variety of different diseases that are triggered by faulty cone cells at the back of the eye.
The problem affects millions of people in this country and can lead to diseases such as macular degeneration, which often causes complete blindness.
Men are most commonly affected by colour blindness. About 8 per cent find it difficult to differentiate between, for example, red and green.
The research, led by Jay Neitz, professor of ophthalmology at the University of Washington, has been published in the scientific journal Nature.
Professor Neitz said: “People who are colour blind often feel that they are missing out. If we could find a way to do this with complete safety in human eyes, as we did with monkeys, I think there would be a lot of people who would want it.
‘We hope this will be useful in correcting lots of vision disorders’
“Beyond that, we hope this technology will be useful in correcting lots of different vision disorders.”
Professor Neitz and wife Maureen, also a professor of ophthalmology, began training the two squirrel monkeys – whom they named Dalton and Sam – to recognise colour more than 10 years ago.
For the new research, the animals’ colour receptor cone cells were injected with a pigment gene but it wasn’t until weeks later that they began to differentiate between red and green.
Scientists also devised a technique called the Cambridge Colour Test, which enabled the monkeys to tell them what colours they were seeing.
The tests are similar to ones that are given to children. Subjects are asked to identify a specific pattern of dots placed among a field of others that vary in size, colour and intensity.
The team of researchers in Washington came up with a computer touch-screen that the monkeys could use to trace the colour patterns. When the animals chose correctly, they were given a reward.
Ophthalmic molecular geneticist, Professor William Hauswirth, of the University of Florida, believes the developments were extremely encouraging and offered the hope of a safe treatment for cone cell conditions.
He said: “Although colour blindness is only moderately life-altering, we’ve shown that we can cure a cone disease in a primate, and that it can be done very safely.
“That’s extremely encouraging for the development of therapies for human cone diseases that really are blinding.”
