The last few years have seen major advances in gene therapy. Following on from the work of Alain Fischer's team on childhood immunodeficiency syndromes, and the recent approval of a therapy in Europe for a metabolic disease, it now seems possible to apply these therapies to a number of conditions. Ophthalmology has been a pioneer in this field, thanks to an excellent understanding of the molecular physiology of the retina, the accessibility of the tissue, the relatively limited size of the injection zone and the possibility of observing any therapeutic benefits precisely and almost quantitatively. The vectors used must target retinal tissue according to the cell type to be targeted, but also regulate expression from specific promoters and considerably reduce any immune phenomena induced by these vectors.
A great deal of work has been carried out in this field, and there are many gene therapy trials underway, with, in the very near future, the approval of the first ocular gene therapy following the work of Jean Bennett's team in Philadelphia.
The main vector used in the retina is the adeno-associated virus (AAV), but lentiviruses are also used to deliver proteins encoded by large genes that cannot fit into an AAV.
Gene therapy involves either gene correction, the administration of therapeutic proteins as a trophic factor, or, in a more recent approach, the administration of light-sensitive proteins, a technology known as optogenetics, discussed in the seminar and at the final symposium.
