Sue Gyford: A new vision of hope for the blind

Published on Wednesday 21 January 2009 08:44

STEM cell research is a subject almost guaranteed to prompt mixed reactions. As if to illustrate that fact, two high- profile Scottish stem cell trials were announced this week, to very different responses. While one was branded "immoral and unethical" by critics, the other was warmly welcomed as offering a potential cure for some types of blindness.

The difference is that the former – a trial in Glasgow to insert stem cells into the brains of stroke victims – relies on stem cells harvested from human embryos, which must be destroyed to enable the beginning of a cell line.

The other, based in Edinburgh, uses stem cells from voluntary adult donors, harvested after their death, to treat corneal blindness.

It is the use of voluntary adult donors that makes all the difference to those with moral and ethical objections to stem cell therapy.

Consultant ophthalmic surgeon Professor Bal Dhillon (pictured below) of the Princess Alexandra Eye Pavilion in Chalmers Street hopes his team's treatment for corneal blindness could restore the sight of millions around the world. Currently, patients who suffer damage to their cornea through accident or illness can only be relieved of the resulting pain and sight loss through corneal transplants. These, however, carry the risk of rejection and infection.

The treatment involves removing cells from the cornea of an adult donor. The cells are grown in a laboratory before being transplanted into the damaged cornea to – hopefully – replace the damaged cells.

Twenty patients will be selected from around Scotland for the trial, which runs until 2011 in Edinburgh and at the Gartnavel General Hospital in Glasgow. If it proves successful, the treatment could be available on the NHS.

Asked if he had encountered any opposition, Prof Dhillon is unequivocal. "No. Because we're using tissue that's been generously donated by adult donors after death, those issues don't arise with this type of research.

"I think the term 'stem cell' has become rather emotive in that it's linked with a number of images and issues, both ethical and moral, associated with the use of foetuses, and this trial is not using foetal stem cells. But I think it's important for clinicians, scientists, and the public to have an open debate."

The Catholic Church has been one of the strongest critics of the use of embryonic stem cells, but positively welcomes the use of adult cells. In April 2007, the church praised work by Sir Magdi Yacoub to grow part of a human heart from adult stem cells, saying it vindicated its position that the use of embryonic cells was "fruitless and destructive". Prof Dhillon's work has also met with approval.

Peter Kearney, a spokesman for the church in Scotland, said: "This appears to be an ethical process. The position of the church is in principle we do support stem cell research and see it as potentially very promising, but make a distinction depending on the source of the stem cells.

"If the stem cells come from adult sources where consent has been given, that's fine. If they're taken from embryos which are created or destroyed or aborted, then it becomes morally unacceptable."

The debate is not over, however, even for Prof Dhillon's treatment.

John Ansell is scientific director of the UK Stem Cell Foundation, which has helped raise funding for the research from the Medical Research Council, Scottish Enterprise and the Scottish Government's Chief Scientist Office.

If the trial proves successful, further ethical dilemmas could arise. He said: "What follows on from that is to what extent these kind of treatments can have eventual applications and the bottom line is if they're going to be used to solve common problems like corneal blindness, you're going to need a lot of cells, and the question is where do you get them from.

"Unless you can find ways of extending the cells which grow corneas to cover the need, then you're going to need to another source and embryonic cells are easier to expand to give you the required numbers – but all these things will be worked out in future."

Regardless of ethical dilemmas, the Eye Pavilion's ground-breaking work has also highlighted Edinburgh's emerging role as a centre of excellence in eye care.

RNIB Scotland spokesman Ian Brown said: "Scotland has a growing reputation as a centre of excellence for eye health and this new treatment will only add to that. We've had good experts here and I think there's been a recognition here among government and health care services of the importance of eye care. For example, you can get free eye tests here, and the drug Lucentis, for macular degeneration, was approved here ahead of England and Wales."

Prof Dhillon agreed: "I think Edinburgh is probably the best place that I've worked. There is an ethos here that part of an NHS consultant's remit is to engage in clinical research in order to make for safer and more effective treatments. I've worked in London, Birmingham, Plymouth, and there's no doubt that the interest, enthusiasm and the number of collaborations are best in Edinburgh. "