be safe moreover as a secondary outcome improvement in visual function was observed in seven of the first nine treated patients n engl j med 358 2231 9 2008 n engl j med 358 2240 8 2008 n engl j med 358 2282 4 2008 hum gene ther sep 7 epub ahead of print 2008 these data demonstrate that gene delivery can be effective for the treatment of an otherwise incurable ocular disease the viral vectors used in each of the studies demonstrate that various gene therapy viral vector designs can be useful for gene deliver methods of viral vector design and generation are well known to those of skill in the art and methods of preparation of viral vectors can be performed by any of a number of companies as demonstrated below expression constructs provided herein can be inserted into any of the exemplary viral vectors listed below alternatively viral vectors can be generated base on the examples provided below for example in the bainbridge study the tgaag76 vector a recombinant adeno associated virus vector of serotype 2 was used for gene delivery the vector contains the human rpe65 coding sequence driven by a 1400 bp fragment of the human rpe65 promoter and terminated by the bovine growth hormone polyadenylation site as described elsewhere the vector was produced by targeted genetics corporation according to good manufacturing practice guidelines with the use of a b50 packaging cell line an adenovirus adeno associated virus hybrid shuttle vector containing the tgaag76 vector genome and an adenovirus 5 helper virus the vector was.