Development of Gene Therapy-based strategies for the treatment of eye diseases

Gene therapy, which is the deliberate transfer of DNA for therapeutic purposes, can be defined as the in situ production of a therapeutical material within the diseased cells. The eye is an ideal target for gene therapy, as it is confined to a small space, separated by the retina-blood barrier from other organs, there are a limited number of cells present, and the endpoint can be optically monitored. Following subretinal injection, recombinant adenovirus and recombinant adeno-associated viruses successfully transduced retinal cells. Of the retinal cells, retinal pigment epithelial cells were transduced with the highest efficiency. The expression of the transgene was transient in adenovirus-injected eyes, in contrast, the expression of the transgene in adeno-associated virus-injected eyes was present throughout the 3-month examination period. These observations suggest that gene therapy with adeno-associated virus could be a suitable approach for the treatment of genetic diseases of the retinal pigment epithelium and adenoviruses for the transient regulation of gene expression in retinal pigment epithelial cells. Drug Dev. Res. 46:277-285, 1999. (C) 1999 Wiley-Liss, Inc.