Liver transplant patients may hold secret to preventing blindness

Patients who have received liver transplants may hold the secret to preventing age-related macular degeneration (AMD), which is a leading cause of blindness in the elderly.

A chemical fault in the liver is known to be more common in people who suffer from this complex eye condition. Now doctors at Southampton General Hospital want to know what happens when patients receive a new liver without the fault.

If receiving a liver transplant without this fault is shown to reduce the onset of AMD, then it might be possible to prevent the eye condition by correcting the fault in patients who originally carry it in their liver.

The investigation is being led by Professor Andrew Lotery, a professor of ophthalmology at the University of Southampton and Dr Sam Khandhadia, clinical ophthalmologist at Southampton Eye Unit and a PhD student in Professor Lotery’s laboratory.

Scientists have already revealed that a fault in a gene that plays an important role in the liver, called complement factor H (CFH), is more common in AMD sufferers, possibly by causing more inflammation in the eye.   

Professor Lotery and Dr Khandhadia hope to discover whether the damage could be prevented if the faulty gene is replaced.

As well as working with Dr Kathryn Nash, a liver expert in Southampton, Dr Khandhadia is travelling to liver transplant units in Birmingham, Cambridge and London to examine the eyes of liver transplant patients for signs of AMD and will establish which patients carried the faulty gene originally.

He will then be able to determine whether receiving a donor liver with a normal, fault-free copy of the gene lowers the risk of developing AMD.

If successful, the study could lead to the development of therapies for preventing AMD via the introduction of fault-free genes – a form of “gene therapy”.

“The outcome of this research may increase our understanding of AMD,” Dr Khandhadia said.

“The project may also offer a novel treatment approach for preventing AMD, perhaps via liver-directed gene therapy or an injection of cells containing a normal copy of the CFH gene.”

Professor Lotery, who is also a consultant ophthalmologist at the hospital’s eye unit, is one of the world’s leading AMD researchers and will oversee the work, which is being carried out at the University of Southampton’s Vision Research Unit.

“Our project is at the interface of clinical ophthalmology and laboratory based science,” he said.

“We are at the very forefront of research into AMD here in Southampton and we envisage very exciting times ahead in the lab and the clinic.”

Last year, Professor Lotery’s lab team identified a major new genetic association with AMD – SERPING1 – which is faulty in up to 25% of sufferers.

He is currently developing stem cell therapies in a groundbreaking project that could eventually restore sight in AMD patients.

The Vision Research Unit needs to secure £2.5 million in funding over the next five years and will rely heavily on charity the Gift of Sight appeal (www.giftofsight.org.uk) which was established in 2004 to raise money for research into complex eye disease.

Posted on Monday 19 October 2009