Laser technique makes light work of tricky surgery to save eyesight
David Rose
Patients who need sight-saving eye surgery could get their vision back more quickly and avoid infection with a revolutionary laser-surgery technique, surgeons say.
Corneal graft surgery, one of the earliest forms of transplant operation, has been performed for more than 100 years without any fundamental changes to the methods used. But although the operation itself is fairly straightforward, recovery often takes a long time.
By using the latest technology designed for laser eye surgery, surgeons can now achieve a better fit for grafts, putting the pieces together like a jigsaw puzzle and helping to accelerate the healing process. Patients can recover perfect vision with or without their spectacles or contact lenses after about six months, roughly halving the recovery time.
The surgery involves the removal of the central part of the cornea, the clear front window of the eye, and its replacement with a corneal graft - about only 0.5mm thick - from a donor. Traditionally surgeons have done this under the microscope using a "cookie-cutter" knife, with the circular graft being secured to the eye with tiny stitches. But the latest femtosecond lasers can cut the cornea into a precise tongue-and-groove pattern to achieve a better fit with the graft, meaning that surgeons need to use fewer sutures and can remove them more quickly after the operation.
Each pulse of light from the lasers is extremely short, lasting only 50 to 1,000 femtoseconds (or quadrillionths of a second). These ultra-short pulses are too brief to transfer heat or shock to the material being cut, which means that extremely fine cuts can be made with no damage to surrounding tissue.
Previously, patients have had to attend regular check-ups for at least a year to ensure that the stitches did not slip out of place and allow bacteria to infect the eye.
Sheraz Daya, an eye surgeon who has pioneered the use of the technique in Britain at the Centre for Sight clinic in East Grinstead, West Sussex, said that patients also recovered their sight more quickly than usual after the operation.
Of six NHS and private patients whom Mr Daya has operated on using the technique, most recovered perfect vision after six months, he said, including two who now no longer need to wear spectacles.
He suggests that the lasers could be used in about half of the 2,500 corneal transplant operations carried out in Britain each year.
"Rather than trying to attach the flat surface of the eye to a flat surface, with the femtosecond laser we can precisely cut the graft to fit on the eye, forming a stronger bond," Mr Daya told The Times. "This means fewer stitches are required, and they can be taken out after just a few months. Patients can cut down on the time off work and also recover their vision quicker, as it is usually fuzzy or misty in the affected eye until the cornea settles down. Most get an acceptable degree of vision back within three months, which becomes perfect by about six months."
Dr Daya added that the new technique also reduced the chances of fragile cornea grafts being torn during the cutting process.
Larry Benjamin, honorary secretary of the Royal College of Ophthalmologists and an eye surgeon at Stoke Mandeville Hospital, in Buckinghamshire, said that the new technique could also avoid astigmatism, where the transplanted cornea becomes misshapen, producing blurred images, and may require further surgery.
Clear sightedness
- 2,403 people had their sight restored by cornea transplants in Britain last year
- 93 per cent of corneal grafts are still functioning after one year and 72 per cent after five years. Many will continue to function for many more years after that
- The first successful cornea transplant was reported in Olmütz, Moravia (now in the Czech Republic), in December 1905
- Last year 1,867 people donated their corneas to be used after their death, but there is still a shortage in