Twelve months after receiving an experimental gene therapy for a rare, inherited form of blindness, a patient discovered that she could read an illuminated clock in the family car for the first time in her life. The unexpected findings suggest that the brain can adapt to new sensory capacity, even in people who have been blind since birth.
The patient, who remains anonymous, suffers from a disease called Leber congenital amaurosis, in which an abnormal protein in sufferers’ photoreceptors severely impairs their sensitivity to light. “It’s like wearing several pairs of sunglasses in a dark room,” says Artur Cideciyan, a researcher at the University of Pennsylvania in Philadelphia, who oversaw the trial.
At the start of the study, physicians injected a gene encoding a functional copy of the protein into a small part of one eye–about eight-to-nine millimeters in diameter–of three patients, all in their twenties and blind since birth. In preliminary results published last year, Cideciyan and colleagues found that all three patients showed substantial improvements in their ability to detect light three months after treatment.