Hope for LCA patients comes in the form of a handsome long-haired French sheepdog known as a Briard. Briards are prone to developing a type of LCA caused by the inability of a layer of eye tissue beneath the retina—the retinal pigment epithelium (rPe)–to produce a normal version of the rPe65 protein, an enzyme that is vital to sight. A veterinary ophthalmologist at the University of Pennsylvania bred a colony of these dogs, some of which are born blind because of an rPe65 defect.

Penn scientists and their colleagues have shown that gene therapy—injecting viruses containing a normal RPE65 gene into the subretinal space—can restore vision in the Briards. Within weeks, the treated eyes are producing normal rPe65 protein.

HHMI investigator Edwin M. Stone is of course enthusiastic about these results: "Researchers took a blind dog—a dog that walked into walls and other obstacles—and changed it into one that could trot around, avoid chair legs, and catch a ball of socks in mid-air." He says the results have held up for more than five years and that about 40 dogs have been successfully treated.

That's potentially good news for people with the rPe65 defect, and human trials are in fact gearing up. But only a limited population of LCA patients—about 10 percent—have this subtype. Still, Stone says, Project 3000 will help find candidates for human trials with this therapy, as well as for other treatments as they become available.

HHMI INVESTIGATOR