Development of gene therapy-based strategies for the treatment of eye diseases

Gene therapy, which is the deliberate transfer of DNA for therapeutic purpo ses, can be defined as the in situ production of a therapeutical material w ithin the diseased cells. The eye is an ideal target for gene therapy, as i t 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 ad enovirus and recombinant adeno-associated viruses successfully transduced r etinal cells. Of the retinal cells, retinal pigment epithelial cells were t ransduced with the highest efficiency. The expression of the transgene was transient in adenovirus-injected eyes, in contrast, the expression of the t ransgene in adeno-associated virus-injected eyes was present throughout the 3-month examination period. These observations suggest that gene therapy w ith adeno-associated virus could be a suitable approach for the treatment o f genetic diseases of the retinal pigment epithelium and adenoviruses for t he transient regulation of gene expression in retinal pigment epithelial ce lls. Drug Dev. Res. 46:277-285, 1999. (C) 1999 Wiley-Liss, Inc.