Gene therapy in age related macular degeneration and hereditary macular disorders.

: In ophthalmology, administration of the therapeutic agent can be difficult due to the tight barriers in the eye. Multiple injections may be needed to allow the therapeutic agent to reach adequate levels in retina and choroidea which may increase the risk of complications including endophthalmitis, cataract and haemorrhages. Optimal methods for the delivery of therapeutic agents to the posterior segments of the eye have not yet been developed. Gene therapy offers an alternative where the therapeutic protein or proteins can be induced in the target tissue for a prolonged period of time after a single injection. The eye is a promising target for gene therapy due to its small size and tissue boundaries preventing leakage of the therapeutic material to other tissues or systemic circulation. However, most of the work in ocular gene therapy is still at the preclinical phase; only three vectors have reached phase 1/2 clinical trials. This review summarizes basic principles and current status of gene therapy in age related macular degeneration and hereditary macular disorders.