A GRANDMOTHER who suffers from corneal blindness has undergone pioneering stem cell replacement treatment which could restore her sight.

Sylvia Paton, 50, from Corstorphine in Edinburgh, was born with aniridia, a rare condition that causes incomplete formation of the iris and loss of vision which usually affects both eyes.

Mrs Paton has no discernible iris, meaning she has only a large dilated pupil. Her vision is also affected by environmental surroundings, daylight and darkness, space, colours, distance and speed. She normally uses dark glasses to protect her eyes.

As a result, she is extremely short-sighted and has just 10% of the vision of a sighted person.

Mrs Paton, a personal assistant, was one of two patients to have the stem cell treatment, which has been developed by Scottish scientists and clinicians, and is said to be the first trial of its kind in the UK.

It involves growing stem cells from deceased donors and transplanting them on to the patient's cornea, the transparent front part of the eye. Scarred and damaged parts of the cornea are removed before the transplant takes place.

Doctors say it could reverse corneal blindness.

Mrs Paton underwent the three-hour procedure 12 weeks ago in the hope it would improve her quality of life, but also because she believes it has the potential to change the lives of millions of others and provide more research opportunities.

The success of the procedure will not be determined for another nine months.

Mrs Paton said: "It has the potential to save vision, protect and give back vision to people like me. Even if only a little of my vision is restored, it would be better than nothing. Plus, it means the team has gained valuable experience.

"My vision is deteriorating as I get older, much the same as other people's. However, I already only have around 10% of the vision of sighted people.

"Until now there's really nothing that could be done to combat the effects of this type of blindness. Not only could this treatment in time be beneficial for millions of people who suffer from corneal blindness but it could also help my son, who also suffers from the same disease."

Mrs Paton met Health Secretary Nicola Sturgeon at the Princess Alexandra Eye Pavilion in Edinburgh yesterday.

Ms Sturgeon said: "This pioneering new treatment could potentially restore sight and improve the lives of many patients, and it is vital we continue to invest in innovative projects such as this one.

"Sylvia is a very real example of how corneal blindness can have a dramatic impact and this trial could potentially transform her life.

"If [it] proves to be successful, we could see many more people benefit as a result. Corneal epithelial stem cell transplantation represents one of the first of a new generation of regenerative therapies which we hope will transform medicine over the coming decades."

Corneal diseases are said to be second only to cataracts as the major cause of blindness and around 20 million people are thought to be affected worldwide.

Dr Ashish Agrawal, a consultant ophthalmologist at NHS Lothian who performed the operation, said: "It is now 12 weeks since the transplant procedure and I am delighted to report that Sylvia is recovering well.

"Her cornea is clear and I hope it will continue to maintain clarity as she goes into the future.

"However, this is the first and the major step in the complex visual rehabilitation process and she will require further surgical treatment to restore vision.

"This study will significantly enhance our understanding of these complex corneal problems and provide us with a great opportunity to further help our patients."