Archived news articles - 2008

The Straits Times, 29 April 2008

Scientists restore eyesight of four

Gene procedure gives hope to those with rare eye disorder

By Liaw Wy-Cin

RESEARCHERS have, for the first time, used gene therapy to improve the eyesight of patients with a rare disorder and in danger of going blind. The procedure used on six patients has been hailed as a breakthrough in a field plagued by failures. Four of the six had improved eyesight.

The work of two international groups from the United States and Britain was reported in separate papers in the New England Journal of Medicine on Sunday. They injected millions of copies of a gene into the patients' retinas. A mutation of this gene causes the blindness.

None of the patients regained normal vision, but the four showed marked improvement. Among them was 18-year-old Steven Howarth, who underwent the pioneering operation at Moorfields Eye Hospital in London. Before the operation, he could hardly see at night and was depressed by the prospect of going completely blind in time, the BBC reported. After surgery, his night-time vision improved so much that he could see clearly enough to walk home from the railway station. 'To not worry about losing my sight is great,' he told the BBC.

Surgeon James Bainbridge, who did the operation, said: 'It's hugely rewarding and exciting to see that this new treatment can have this impact on a person's quality of life.' He added that what the operation has shown is that gene therapy can be used to treat a particular gene disorder, and 'this is only the beginning'.

The six patients had a rare inherited disorder called Leber's congenital amaurosis, which begins eroding eyesight at birth, eventually leaving them blind before they reach 30. Its prevalence in Singapore is not known, with eye specialist Au Eong Kah Guan saying that it affects three in 100,000 newborns.

Gene therapy is deceptively simple - the idea is to replace a faulty gene by using a virus to carry a new version of the gene into a patient's cells. But such research has been dogged by failure since the technology became available almost two decades ago. The latest breakthrough, however, has highlighted the potential of the field, say researchers.

Experts say gene therapy may work particularly well with eye disorders because the immune system, which can reject the virus carrying the genes, is not as active in the eye. And because it is easy to test vision, doctors know quickly whether the therapy works.

The executive director of the Genome Institute of Singapore, Professor Edison Liu, said of the breakthrough: 'This is very good because it helps people.' But he cautioned that the success of this work on the eye could not be easily translated into curing other diseases.

Dr Kong Hwai Loong, 43, senior consultant medical oncologist at Mount Elizabeth Medical Centre, said the pioneering work had produced 'very tantalising results' sure to revive interest in human gene therapy. 'However, until more in-depth and longer-term studies are carried out, this approach remains experimental,' he added.