Reflection on the efficacy of gene therapy in the treatment of inherited retinal degeneration

Inherited retinal degeneration is a group of genetic retinal disorders characterized by the death of photoreceptor cells. Over 150 genes are associated with inherited retinal degeneration; the proteins encoded by these genes are required not only for photoreceptor development, maintenance, photo transduction and synaptic transmission but also for retinal pigment epithelium cell integrity and function [1]. The use of animal models of inherited retinal degeneration facilitates understanding of the underlying disease mechanisms and allows assessment of preclinical gene-replacement treatments. Gene therapy has been performed in animal models with different types of retinal degeneration (e.g. Leber congenital amaurosis (LCA), retinitis pigmentosa, and cone-rod dystrophies) and has been shown to significantly improve visual function [2]. Clinical characterization and genetic diagnosis of patients with inherited retinal diseases offer opportunities for the evaluation of gene therapy in clinical trials.