Amelioration of one form of early-onset retinal degeneration caused by the gene RPE65 has been demonstrated following sub-retinal administration of recombinant adeno-associated virus (AAV) encoding the complete RPE65 coding DNA sequence.2, 3, 4 Other forms of inherited retinal degeneration may be amenable to rescue following this strategy; however, the genes associated with the most prevalent forms of retinal disease exceed the DNA coding capacity of AAV.5 The gene discussed is RPE65; the disease is retinal degeneration.