School of Medicine

Department of Ophthalmology - News

Girl's Sight Restored in NZ First

How The Corneal Transplant Works

Natalya Skelton (6 years) went blind in one eye after a bout of chickenpox damaged the front part of her cornea. In a NZ first operation Professor Charles McGhee performed a new type of corneal graft ('DALK' - Deep Anterior Lamellar Keratoplasty) to replace the damaged part of her cornea with healthy donor tissue. Charles and Natalya have been profiled in the NZ Herald and on TVNZ's 'Close Up'.

From the NZ Herald article:

Natalya Skelton went blind in one eye when she was 3 after suffering a severe complication from a virus.

But now, three years later, after an international search for a surgeon willing to take on such a young child, Natalya's sight has been restored by a delicate corneal transplant operation, a New Zealand first for one so young.

The blindness in Natalya's left eye started lifting within days of the surgery at the Greenlane Clinical Centre early last month.

Now 6, Natalya went with her mother, Kirsten Anderson, yesterday for a check on her corneal transplant with her Auckland District Health Board eye surgeon, Professor Charles McGhee.

She said she loves her "new eye".

"Because I can now see colours and stuff. And I like to paint pictures of McTum. He's Charles' fat cat."

In September 2006, Natalya caught chickenpox, a virus which for most children causes just a mild infection and itchy, troublesome blisters.

In Natalya's case, however, it is thought the ulceration and scarring that damaged her left eye's cornea was caused either by the chickenpox or the virus which causes coldsores.

Ms Anderson, from Queenstown, said she initially had difficulty finding comprehensive treatment for Natalya after her eye became red and painful.

"Suddenly, I found myself driving well above the speed limit to Invercargill to try and arrest a huge lesion that appeared in Natalya's left eye.

"It was black and red and swelling by the minute.

"We arrived at Southland Hospital, but it was too late; the damage had been done. She had lost the surface of her cornea and the tissue underneath."

The cornea is the clear layer at the front of the eye.

"It was like having a coldsore in your eye. There was nothing that could be done, other than steroids and a hope that she wouldn't lose the eye altogether," Ms Anderson said.

"For the next three years we endured a system which offered us little hope or help. 'She'll be blind from now on,' they said, 'and that's sad, but look on the bright side: she has one good eye and she'll manage with that'."

Ms Anderson said she was furious, and sad, but did not give up hope. She searched internationally for help and eventually found Professor McGhee.

He said Natalya now had about 30 per cent normal vision in her left eye and he expected this would eventually increase to around 80 per cent - good enough for a driver's licence.

But she still faced risks such as her body rejecting the transplant, a flare-up of the original virus - she is on anti-viral medication to minimise this risk - and knocks to the eye.

She has 16 tiny stitches in her eye to help the corneal transplant, from a deceased donor, to attach to the remaining parts of her own cornea. The stitches will be removed after about a year.

Professor McGhee said four children aged 6 or younger, including Natalya, had had corneal transplants in the past decade in New Zealand.

Three were the traditional operation that removed a full-thickness "button" from the cornea, but Natalya's was a newer, more technically demanding approach which slowly sliced through the cornea's microscopic layers and left the inner layers in place.

A normal cornea is 0.5mm thick, but the damage to Natalya's meant it was just half that in places. The inner layers are 0.05mm, the thickness of a human hair.

The surgeons look through powerful microscopes and use hand-held blades and a "trephine", a circular blade whose frame "sucks" on to the cornea.

Leaving the lower corneal layers reduces the chances of Natalya's body rejecting the transplant, because the corresponding layers can be removed from the donor graft and it is one of these layers that is involved in immune system rejection.

Around 250 corneal transplants are done each year in New Zealand, and there is a constant need for donated corneas.

More than half of people who die are suitable eye-tissue donors.

For information on donation, call the National Eye Bank, 0800-373-7537

5 December 2009