Hereditary retinal disease affects our most precious sense, sight, in about 1 in 3000 of the population. Many of these disorders cause complete loss of vision blindness and, unfortunately, there is as yet no effective treatment. A major difficulty in developing treatments is the inability to sample retinal tissues from patients in order to fully understand how the disease develops or to test novel treatments that may further compromise limited vision. The use of animal models avoids these problems but, to be meaningful, they need to accurately mimic the human disorder. This means that the same gene mutation must be studied. Such mutations are generally not found in nature so the same gene as in human must be targeted in the animal so that the same mutation is introduced. These are complex, time-consuming and expensive experiments, so it is important that such models of human disease are fully exploited. We have already generated two such models with human mutations in genes responsible for basic visual processes resulting in the loss of light sensitive cells in the retina. We propose to use these models to gain a detailed understanding of the process of retinal degeneration and to follow this with an assessment of potential treatment options that will include the testing of various drugs, growth factors and gene replacement therapy using viral vectors delivered to the eye. This will enable us to determine the treatment for patients and will provide the first step towards a clinical trial.