GENE THERAPY RESTORES VISION

Source: Hindustan times
29th April, 2008

Persons with congenital retinal disease get partial sight with experimental method in the US

An experimental gene therapy has helped restore partial vision to persons with congenial retinal disease, according to studies published Sunday in a breakthrough which provides hope for treating various eye illnesses.

In one study, clinical trials showed success on 3 young adults at children’s hospital of the Philadelphia who suffered from a rare and as yet incurable form of congenital blindness.
The retinal degenerations include leber congenital amaurosis, or LCA, a group of diseases that affect light receptors in the retina beginning in early childhood and often causing total blindness in patients in their twenties or thirties.

“This result is important for the enter field of gene therapy”. study leader Katherine High was quoted as saying in a new England Journal of Medicine whose website reported the findings by a collection of international doctors and scientists.

“Gene transfer has been in Clinical Trials for over 15 years now, and although it has an excellent safety record, example of therapeutic effect are still relatively few” High said.

“The results in this study provide objective evidence of improvement in the ability to perceive light, and thus lay the ground work for future studies in this and other retinal disorders.”

Scientists used a genetically engineered virus known as vector to carry a normal version of the gene known as RPE65, which is mutated in the form of LCA, to the patients via surgical procedures performed between October 2007 and January 2008.

About 2 weeks after the surgery all three patients, age 19,26 and 26,reprted improved visions in the injected eye, and became approximately 3 times more sensitive to light than in the other eye, according to study co-author Albert Auricchio from the second University of Naples, in Italy.

“Standard vision tests showed significantly improved vision in the patients” Auricchio said.
There vision “improved from detecting hand movement to reading lines on an eye chart”
Said Albert Maguire, Associate Professor of Opthalmology at the University Of Pennsylvania School Of Medicine.

In 2001 Maguire and his wife Jean Bennett were part of a team which reported successfully using gene therapy to reverse blindness in Dogs affected by the same Congenital blindness.
A separate clinical Trial parallel to the Philadelphia study was conducted at Britain’s University College London, also on three young adults, with one 18-year-old patient showing improved visual function.

Researchers of that study concluded that there were no major adverse effects of the so called Adeno-Associated Virus (AAV) treatment.

“of course, additional studies are needed in order to access the approach fully, including the expansion of the study to include younger children but these initial results suggest that AAV based delivery of Genes in the eye can be accomplished,” said research co-author Barrie Carter, executive vice president of Targeted Genetics.