Eye surgeons stand behind 'miracle' cure

By FIONA BARBER

New Zealand eye specialists are moving to quell patients' fears after an overseas expert warned that a "miracle" vision-correcting laser technique could cause eyeball disintegration.

A British eye surgeon this week said there was growing evidence of long-term damage from the Lasik technique that could lead to the cornea becoming so eroded it could bulge or even dislodge, requiring a transplant.

The claims from John Marshall, a professor of ophthalmology at St Thomas's Hospital in London, have resulted in worried New Zealand patients contacting eye clinics.

It is estimated that more than 5000 patients have undergone the surgery in this country.

Lasik, which costs about $1900 for each eye, uses a laser to change the curvature of the cornea.

It involves scraping a third or more off the thickness of the cornea.

According to reports, Professor Marshall voiced no such fears about another popular laser technique used in New Zealand, PRK, which was developed earlier.

PRK is more painful than Lasik and takes longer to heal.

But the man who chaired the group which penned the British guidelines for the Lasik technique - and who has written a text book on the subject - described the claims as "quite sensationalist."

Charles McGhee, now professor of ophthalmology at the Auckland Medical School, said he believed the method was reasonably safe and was used conservatively in New Zealand.

He had also been involved in a three-year study in Scotland, which found no such cornea-bowing problems in 109 patients.

And even though more than a million patients had been treated with Lasik internationally, there were only seven documented cases of corneas bowing.

"That's not to say there are not issues - people have to follow guidelines," Professor McGhee said.

Problems could arise if surgeons ignored guidelines and cut too deeply.

He also wondered whether some of the problem cases had involved patients with a pre-existing, cornea-bowing condition.

There was a small chance - about 1 per cent - of a patient's eyesight becoming worse after Lasik.

The chances of bowing the cornea were in the region of one in 100,000.

"There are risks and benefits," Professor McGhee said.

An Auckland eye specialist, and spokesman for the Royal Australia and New Zealand College of Ophthalmologists, Bruce Hadden, said all surgery had problems, but he had not seen a case where the cornea had bulged.

"Everyone doing them in New Zealand has the high-tech equipment to measure the thickness of the cornea before the procedure," said Dr Hadden, whose clinic performs Lasik.

"I suspect problems have arisen [overseas] because people have not adhered to clinical standards."

Dr David Pendergrast, an eye specialist and director of clinical operations at the New Zealand eye bank, said each patient had to be assessed carefully.

It had to be decided whether the PRK technique or Lasik was best.

"Because we're operating on human tissue, everyone's eyes respond differently. It [laser surgery] is not as accurate as popularly perceived," said Dr Pendergrast.

"It's not realistic for them to expect they can throw away their glasses."