High-tech corrections to short sight are growing in popularity, but it is too early to assess long-term results, says Christine Doyle
IN THE brave new "visionary" world, eyesight problems will be assessed with the help of computer calculations and remedied with a few zaps of the latest laser. The groundbreaking "flap and zap" technique for severe short sight (see below) is evidence of rapid advance.
Up to 25,000 people in Britain have already had moderate short sight corrected by laser surgery (photoreactive keratectomy, or PRK) and with an estimated 10 million more sufferers, the potential for further operations is vast. Eye clinics advertise daily how, by spending from £395 to £1,400 an eye, you can fulfil the dream of seeing without glasses.
Treatment with an excimer laser involves shaving microscopic layers of cells from the cornea to bring images into sharp focus on the retina rather than in front of it, as in short sight, or behind it, as in long sight. But is laser surgery on basically healthy eye tissue truly safe?
A more cautious approach was recently recommended by Mr David Gartry, of Moorfields Eye Hospital in London, the first surgeon to pioneer laser eye surgery in Britain at St Thomas' Hospital in 1988. In a review in the British Medical Journal, he gave a warning that although 85 per cent of patients were pleased with laser surgery, 15 per cent lost some visual acuity. A further 10 per cent reported haloes around lights at night that could make driving difficult.
Others, such as Mr William Jory, consultant ophthalmologist at the London Centre for Refractive Surgery, say that little is known about the long-term effects of thinning of the cornea or creating shock waves on its inner layer. He cites Japanese experience in the Fifties, when surgery to both the front and back of the cornea led to blindness 18 years later.
Mr Gartry, among other leading eye specialists, is less pessimistic than Mr Jory. PRK had not, he agreed, been in use long enough to assess fully the long-term results. Yet, he pointed out, thousands of people (the precise total is not known) in this country and Europe had had laser correction of short sight since its start in 1983, and blindness had not yet proved a problem.
None the less, Mr Gartry stressed that laser surgery was by no means 100 per cent predictable, especially for more severe short sight. Patients should "be critical, seek as much information as possible and not have unrealistic expectations". Laser eye surgery is not suitable for, among others, pregnant women, people with very dry eyes, diabetics or those on immunosuppressant drugs.
PRK eye surgery is still not licensed for use in America, except in strictly controlled research circumstances, though that may change soon. Some European experts favour much more regulation on this side of the Atlantic. Mr Jory said laser eye surgery "should be carried out only in approved clinics attached to hospitals where operations can be independently assessed".
At present, it is up to individual surgeons or clinics to collate their own results. Russell Ambrose, chairman of the Optimax chain of laser surgery clinics, said: "We've treated around 13,000 people in Britain. We counsel everyone first and measure the results independently with a computer questionnaire. Only four per cent are 'disappointed'." But there are up to 50 independent eye laser clinics and no widely acknowledged clinical recording system.
Mr Gartry said: "Some system for collating results would be useful. But we also look to theRoyal College of Ophthalmologists and surgeons themselves to set and monitor standards and minimise risks. To this effect, the college has this year published guidelines to the best clinical practice, as well as a recommended informed consent form. It has also produced a booklet for patients."
Those who think it anathema to tamper with healthy eyes will not be tempted by the high-tech solution. And with such fast-moving technology, others may prefer to wait until the lasers - and the monitoring of results - are more predictable.
