Gene therapy gives sight to blind

Thursday February 9th, 2012

A gene therapy treatment for people with congenital blindness has now been used to give sight to both eyes, researchers announced last night.

And several years after attempting the first therapy, doctors are now hopeful that the treatment will prove permanent.

Three people have now had the treatment in both eyes and have enough sight to walk an obstacle course.

The treatment has been developed for Leber congenital amaurosis, which causes blindness at birth or shortly afterwards, and is caused by a mutation in the RPE65 gene.

Researchers led by Jean Bennett, of Pennsylvania University, Philadelphia, USA, and scientists at Naples University, Italy, and the Telethon Institute of Genetics and Medicine in Naples have reported their findings in Science Translational Medicine.

The researchers were worried that the patients would have developed immunity to the gene therapy - which uses a virus "shell" to infect the eye with the new gene.

But they found no evidence of this when they treated the second eye - and say this may be because the eye has a unique ability to tolerate unfamiliar substances.

The success of the treatment was confirmed with functional MRI scans.

"Treatment to the second eye appeared to be just as effective as the first," they write.

The researchers now plan to offer more treatment to the other nine patients in the first trial

Science Translational Medicine February 8 2012

Tags: Europe | Eye Health | Genetics | North America

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