New gene therapy operation offers hope to blind
Thousands of people with previously incurable forms of blindness could have their sight restored thanks to a pioneering gene therapy that requires only one operation.
In what scientists called a "very promising" first trial, six patients have been successfully treated for choroideremia, an inherited disease which leads to a gradual loss of sight and, eventually, total blindness.
While the condition itself is rare, the success of the new treatment holds out the hope that similar methods could be used to halt the progress of other genetic causes of blindness -- including age-related macular degeneration, the most common cause.
The treatment, carried out by a team of scientists led by the University of Oxford's Professor Robert MacLaren, halts the damage done by choroideremia by restoring a defective gene in the retina.
In sufferers, a lack of proteins produced by the defective CHM gene leads light-sensitive cells in the retina to slowly stop working, and eventually die off. The disease is often diagnosed in childhood. As it progresses the surviving retina gradually shrinks in size, reducing vision.
Professor MacLaren and his team found a way of restoring a working CHM gene to the eye by transporting it in the cell of a harmless virus, injected underneath the retina with a fine needle.
The gene then produces the necessary protein, repairing the remaining light-sensitive cells and halting the shrinking of the retina. Professor MacLaren said the technique could be available widely within three to five years. © Independent News Service)