New Gene Therapy Enables Patients with Congenital Blindness to See

By Ed Martinez

October 25, 2009

A new treatment that represents a major milestone toward medical science’s goal of using gene therapy to cure disease was recently administered on patients suffering from congenital blindness.

The study, conducted by researchers from the Center for Cellular and Molecular Therapeutics at the Children’s Hospital of Philadelphia, revealed dramatic vision improvements on five children and seven adults in just two weeks after the first injections were issued.

The greatest improvements were noticed in the children. “Children who were treated with gene therapy are now able to walk and play just like any normally sighted child," said Albert M. Maguire, M.D., a physician at the Children's Hospital of Philadelphia and a professor of Ophthalmology at the University of Pennsylvania School of Medicine.

Although the patients did not attain normal eyesight, twelve of them improved enough that they might no longer be classified as legally blind. “The clinical benefits have persisted for nearly two years since the first subjects were treated with injections of therapeutic genes into their retinas," noted Jean Bennett, M.D., Ph.D., F.M. Kirby professor of Ophthalmology at Penn.

Bennett also attributed the new findings to nearly 20 years of gene studies on hereditary blindness, starting with pioneering work in mice and dogs. "These remarkable results," she added, "have laid a foundation for applying gene therapy not only to other forms of childhood-onset retinal disease, but also to more common retinal degenerations.”

The next follow-up studies will monitor the patients to determine whether the treatment stops the progression of retinal degeneration. The researchers will also investigate whether this new therapy can be applied to other retinal diseases.