Gene delivery to the retina: focus on non-viral approaches

For more than two decades, gene therapy has sought to treat diseases with a genetic component. The eye is a promising target organ for gene therapy because of its unique features like easy accessibility and convenient methods of direct assessment of visual function as an effect of therapy. Several retinal diseases have been linked to specific genes in combination with environmental factors and hence gene therapy offers hope for a long-term cure for them. Developing novel non-viral routes for delivering therapeutic genes to the retina is emerging as an important area of drug delivery research. In this review, we focus on different non-viral vectors for gene delivery to the retina, the barriers that such delivery systems face and methods to overcome them.