¹Division of Molecular Therapy, Institute of Ophthalmology, University College London, London, UK

Correspondence: Professor RR Ali, Division of Molecular Therapy, Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK. E-mail: r.ali@ucl.ac.uk

Received 3 January 2006; Revised 5 May 2006; Accepted 19 May 2006; Published online 13 July 2006.

Abstract

The eye has unique advantages as a target organ for gene therapy of both inherited and acquired ocular disorders and offers a valuable model system for gene therapy. The eye is readily accessible to phenotypic examination and investigation of therapeutic effects in vivo by fundus imaging and electrophysiological techniques. Considerable progress has been made in the development of gene replacement therapies for retinal degenerations resulting from gene defects in photoreceptor cells (rds, RPGRIP, RS-1) and in retinal pigment epithelial cells (MerTK, RPE65, OA1) using recombinant adeno-associated virus and lentivirus-based vectors. Gene therapy also offers a potentially powerful approach to the treatment of complex acquired disorders such as those involving angiogenesis, inflammation and degeneration, by the targeted sustained intraocular delivery of therapeutic proteins. Proposals for clinical trials of gene therapy for early-onset retinal degeneration owing to defects in the gene encoding the visual cycle protein RPE65 have recently received ethical approval.