A mouse, soaking wet, is scooped up in the warm hands of a researcher. It has just paddled its way through a tub of water and climbed onto a platform, getting a welcome break from swimming. The researcher had trained it to associate the hidden resting spot with a nearby flickering light, and if this were any other mouse, the fact it could remember how to find the platform using visual cues would be a testament to the animal’s ability to learn. But this isn’t a typical rodent: this mouse used to be blind. The mouse’s sight had been restored by gene therapy developed in the lab of John Flannery, UC Berkeley Professor of Optometry and Vision Science. The lab’s goal is to understand mechanisms underlying retinal degenerations and use that information to develop rational treatments for blinding diseases. Before treatment, the mouse was blind due to a genetic mutation that causes a condition mimicking retinal disease in people. Genetic retinal degeneration disorders are a common cause of complete blindness in humans, affecting one in three thousand people worldwide.
Over 250 mutations that cause genetic types of blindness such as the one affecting this mouse have been found, and more continue to be discovered. Curing the rodent is a proof of concept: the fact that the treatment works for mice with one mutation means that it might be possible to adapt the therapy to treat similar problems in people.
Read more from Berkeley Vision Science: https://vision.berkeley.edu/posts/repairing-the-retina