We were really very, very excited when we first got a glimmer that we had actually restored vision to these dogs which had been previously blind. It could also help hundreds of thousands of others with similar forms of blindness. Over time, the retina deteriorates and becomes dysfunctional in people with this disorder, so scientists say children would be the most likely beneficiaries of the gene therapy. There is a lot to be done first before researchers can advance to human trials, said Dr. Gregory Acland, a research veterinarian at Cornell University. Acland says he expects it will take about four years to get to that point.
Researchers have to look at a variety of factors.
Human vision is different from dog vision because there is a different sense of acuity. Researchers would also have to determine the dose, and the frequency of the treatments for humans. Also, gene therapy has a 10-year history of raising false hopes, and the field has been under critical scrutiny since the November 1999 death of a teenager in a gene therapy experiment. As a result, scientists would want to make sure that the therapeutic effect is long term without complications or side effects. In the study, the gene was injected under the retina in one eye of each of the three Briard dogs, Acland said.