New hope for blindness
A surgeon who pioneered laser eye surgery to cure short-sightedness has announced a new technique which could prevent millions of older people from going blind.
Professor John Marshall, a senior ophthalmologist at King’s College, London, has developed a short pulse laser technique which can delay the onset of age-related macular degeneration (AMD).
AMD is the leading cause of blindness in over 60s in the western world and 200,000 people in the UK are currently registered as blind or partially sighted because of it.
Prof Marshall said the treatment delayed the effect of ageing, a process he calls “retinal rejuvenation”, without damaging any other cells.
“The treatment is really treating ageing,” he said.
The technique works by stimulating enzymes to remove waste material from a thin membrane behind the retina, called Bruch’s membrane.
Improvements to sight were reported after the treatment was used in a clinical trial involving more than 100 diabetics.
A new trial will treat patients already suffering from AMD in one eye with the aim of saving the sight in their better eye for as long as possible.
Prof Marshall said once people have advanced AMD in one eye, studies show the condition usually develops in the second eye in 18 months to three years.
“If you can delay the onset by three, four, six, seven or 10 years, it’s proof of the principle,” he said.
He said the aim was to preserve their sight for the rest of their lives.
Prof Marshall said he hoped the treatment would be available within two to five years and one day people in their 40s who have a family history of AMD could choose to have the treatment as a way of preventing the onset of the condition.
Conventional lasers can cause damage to the light sensitive cells in the eye but Prof Marshall said: “With this laser it’s been specifically designed so we don’t cause any damage to the light sensitive cells or to any cells.”
There is currently no treatment for the most common form of AMD – known as “dry” AMD – which the new laser technique could prevent.
The more aggressive “wet” form of AMD – where new blood vessels cause bleeding and scarring behind the retina – can be stabilised with drugs.
Prof Marshall said: “If you look to the age of 80 we all have a 30% chance probability that we will have some visual loss due to the ageing process even if we don’t have the AMD gene.
“All of us will ultimately lose vision if we live long enough.
“That’s why the impact of this rejuvenation is profound.”
Tom Pey, director of external affairs for Guide Dogs for the Blind, which funded the research, said: “This is potentially a huge breakthrough for millions of people across the world.
“The science behind this is proven and, although clinical trials are likely to take years, we hope it will be in the low single figures.
“We must stress though that the work Professor Marshall carried out is primarily going to be a preventative for those who do not yet show signs of AMD.
For those who already are suffering, there is unfortunately unlikely to be major improvements as once the damage is done, as in so many causes of blindness, the effects are irreversible.”
Prof Marshall has worked in the field since the early 1960s and said he first looked at the effects of lasers on the eye after being given a grant by the RAF to investigate the risks.