Researchers at the Hadassah University Medical Center have completed a clinical trial which has successfully demonstrated the efficacy of gene therapy in restoring vision to patients with Leber’s Congenital Amaurosis (LCA), a genetic condition which causes severe visual impairment and eventual blindness.
Those with LCA experience poor night vision, low visual acuity, and a constricted visual field. The low vision continues to deteriorate, until the individual becomes totally blind. Some victims of LCA also suffer from crossed eyes, roving eye movements, unusual sensitivity to light, and/or cataracts. LCA is usually inherited as an autosomal recessive genetic condition.
The study, conducted by Dr. Eyal Banin of Hadassah's Center for Retinal and Macular Degeneration in collaboration with leading researchers in the United States and Great Britain, involved replacing the damaged RPE65 gene with a normal one. The procedure, whereby the gene was injected into the retina, also triggered renewed protein production.
Two participants in the study, Dana and Yossi, were treated with this gene therapy in just part of the retina of one eye, with dramatic results: A few weeks following treatment, both participants noted a substantial improvement in their vision.
"It was amazing because today I see things that I have never seen before," Yossi related. Dana noted that "learning of this new treatment was a life-changing event. I'm experiencing a real change." To hear directly from Dana and Yossi about the success of their treatment, click to http://www.mvrf.org/news.php.
Yossi and Dana's self-reporting of visual improvement is corroborated by objective, quantitative measurements of the treated area. With the continuation of this research, Hadassah's scientists will develop gene therapy to treat additional retinal degenerative diseases. "You cannot imagine what an effect this has had not only on the treated patients and their families," notes Dr. Banin, "but also on the wider population of patients with retinal and macular degenerations here in Israel, who suddenly feel some glimmer of hope." He added that "we feel very fortunate to have Macula Vision Research Foundation (MVRF) as our partners in this very exciting journey. Without funding from MVRF, we could not have conducted this clinical trial."