There is currently no FDA approved treatment for the millions of people suffering from blindness due to debilitating retinal degenerative diseases. It is estimated there are more than 15 million people worldwide that have severe vision loss due to the most common forms of retinal degeneration, retinitis pigmentosa (RP) and age-related macular degeneration (AMD). In 2003, the National Eye Institute estimated the cost of health care and lost wages due to visual disorders and disability to be in excess of $67 billion in the United States.
In normal vision, light enters the front of the eye and activates the photoreceptors of the retina, at the back of the eye. The activated photoreceptors send electrochemical signals through the bipolar and ganglions cells, which are then transmitted back to the brain through the optic nerve for additional, high-level processing such as face or object recognition. This process is call visual perception or, more simply, how we "see". When photoreceptors die, visual impairment or complete blindness occurs because the eye can no longer capture light.
In RP and AMD, the light sensing cells of the back part of the eye (i.e., photoreceptors) become functionally disrupted and die. However, the degenation is generally limited to photoreceptors, sparing the other cellular layers, thus creating an avenue for a therapeutic interface with the remaining functional circuitry of the retina. The Eos Neuroscience approach involves a gene therapy that allows the next order neurons, the bipolar cells, to become sensitive to light. Essentially, after the photoreceptors die off due to RP or AMD, we turn the bipolar cells into photoreceptors, restoring the natural light-capturing ability of the retina. We have established the feasibility of this approach in mulitple mouse models of blindness that mimic human RP. For more detail on this approach, please see the technology section.