SCIENTISTS in Scotland are developing a laser cure that will revolutionise treatment for cataracts, the most common cause of blindness.
The current treatment for cataracts, which blur vision as the lens of the eye becomes increasingly cloudy, is the most common surgical procedure carried out by the NHS, with around 350,000 operations performed annually in the UK and millions more worldwide every year.
Although effective in most cases, surgery involves replacing the clouded natural lens with a plastic alternative and can lead to complications such as infection, especially in the developing world.
Now scientists at Heriot-Watt University in Edinburgh have been awarded £2.7 million by the European Commission and the Medical Research Council to develop a laser therapy that could be used globally.
The potential new treatment emerged while the team was involved in developing a new and more accurate diagnostic test for cataracts, which affect half of people over the age of 65. They found that lasers used at a certain wavelength can affect the molecular structure of the lens, restoring it to its pre-cataract state without the need for surgery.
The grants will be spent over the next three years on developing a prototype mobile laser device. Small-scale clinical trials of the new method will be undertaken by scientific partners of the Scottish team in Scandinavia and Asia.
The new test is in itself a major breakthrough that promises to save millions of pounds for health services globally by preventing unnecessary cataract operations. Instead of relying on the subjective judgment of eye specialists to make a diagnosis, the new method uses measurable changes in the structure of proteins in the lens to detect accurately cataract formation and whether treatment is required.
Both the laser therapy and the test are predicted to help doctors deal with the growing number of cataracts in both older age groups and rising numbers of younger people affected by obesity-related diabetes. Cases of Type 2 diabetes are increasing in Scotland by 5 per cent annually.
Professor Rory Duncan, the head of Heriot-Watt’s Institute of Biological Chemistry, Biophysics and Bioengineering, said: “With an ageing population, a Type 2 diabetes epidemic and over 15 million cataract removals each year globally, there is an immediate need for accurate and timely diagnoses and treatment of cataracts.
“The subjective way that clinicians decide whether or not to surgically remove cataracts can lead to patients being referred for surgery too early, placing stress on healthcare services, or too late, at which point they will have suffered with poor eyesight far longer than necessary.
“We’re developing a quantitative method of diagnosing the presence and severity of cataracts that is objective. This will lead to a reduction in early, late or unnecessary operations and further research will allow us to start diagnosing cataracts much earlier.”
The possibilities of a new laser therapy had been discovered during the development of the test, Duncan said.
“Dehydration, exposure to naturally occurring ultraviolet light over a lifetime and high blood sugar from diabetes are all known to contribute to the formation of cataracts, but only a very sensitive way of detecting the smallest changes in lens proteins can clarify this,” Duncan said.
“Once we know exactly what triggers cataracts and when, we hope to develop laser treatment that could reverse the condition. What we found is that by shining a laser light at a certain wavelength on the protein it changes the structure back to the non-cataract state. We can reverse the process.”
Duncan added that although surgery is highly effective, in most cases it is invasive, which can produce infections.
“Also, with surgery the surgeon has to remove the lens from the front of the eye and pop in a plastic lens,” he said. “It’s better than the cataract but not better than the real thing. If we have a non-invasive therapy and a clear diagnosis then it will allow the patient to keep their own lens.”
The initial work on the new test sprang from the experiences five years ago of Des Smith, the emeritus professor of physics at the university, who now works for spin-off company Edinburgh Biosciences.
“I am a keen sportsman and first noticed that my eyesight was deteriorating when I could no longer follow my golf ball,” said Smith, 82. “It was like looking into a fog.
“Cataracts were diagnosed in both eyes but when I talked to my surgeon about it he said getting the right diagnosis was all down to experience. He knew my background and asked if I could do better than that. I said I would find out.”
From initial studies involving pig’s eyeballs, Smith and his team of optical experts developed the new test for humans.
“We realised this was important as a scientific tool as well as providing early diagnosis.”