Abstract: Degenerative diseases of the retina are a leading cause of vision loss in the United States, affecting approximately two million people each year. The replacement of a defective gene by gene therapy provides one approach for treating individuals having ocular neuronal degeneration where the defective gene has been identified. Several factors, however, suggest that the replacement of a specific gene in a patient might not be effective. For example, many of the conditions are autosomal dominant, and placing a normal copy of the gene into the cells would not correct the defect. As an alternative, replication competent, avirulent, ribonuclease reductase deficient Herpes simplex virus can provide the means to deliver therapeutic polypeptides in a continuous manner to affected cells. Such therapeutic polypeptides include growth factors, neurotrophins and cytokines.