Applications of Gene Therapy in Retinal Disorders

Abstract

Gene therapy holds great promise for the treatment of eye diseases, and proof-of-principle of its efficacy in animal models and humans has recently been provided. Notable progress has been made in understanding the genetic pathogenesis of ocular diseases and improving the safety and specificity of vector-based ocular gene transfer methods. These technical developments have been critical to the gene therapy successes achieved in experimental and clinical trials of retinal ocular diseases. Preliminary successes have been reported in phase 1 clinical trials utilising RPE65 gene therapy for LCA. Higher doses of vector, younger treatment ages and appropriate clinical read-outs will be instrumental in defining the therapeutic potential of this approach for LCA caused by RPE65 mutations. Another major area of emphasis in gene therapy is treatment of wet AMD. Although anti-VEGF drugs are currently successfully treating wet AMD, the cost and time involved in monthly or semimonthly injections can be troublesome while gene therapy is a one-time treatment. PEDF gene therapy for AMD decreases the size and prominence of CNV lesions with high doses of treatment . In retinoblastoma phase 1 clinical trial, Tumor regression was observed at higher doses, though all patiants required enucleation, indicating that gene therapy should not be used alone but might be considered as an adjuvant to standard therapies.