Vectors and Gene Delivery to the Retina.

One of the great advantages of the retina as a target tissue for gene delivery is the wide array of genetic tools that have been developed in the past decade. This includes a variety of vectors for therapeutic gene delivery to most types of retinal neurons and glia, as well as cell type-specific promoters for restricted gene expression in distinct neuronal subtypes. Within the scope of neuroscience applications and for gene therapy, it is now routine to express reporter genes, replacement genes, neuronal activity indicators, and microbial opsins in specific neuronal types in the mouse retina. However, there are considerable anatomical, physiological, immunological, and behavioral differences between the mouse and the human that limit the usefulness of these tools in humans and nonhuman primates. Several advances are now being made toward the goal of applying viral targeting tools to understand the primate retina. Here, we describe these advances, consider their potential to advance our understanding of the primate retina, and describe what will be needed to move forward.