The idea of gene therapy has been discussed in the medical literature since as early as the 1970s. In 1972, Friedman and Roblin proposed that it was theoretically possible to introduce "good" DNA to replace defective DNA.1 Over the years, a number of gene therapy clinical trials emerged in efforts to treat genetic diseases of inborn errors of metabolism, all with varying degrees of success.

The basic principle of gene therapy is to put corrective genetic material into cells to treat genetic disease. Several gene therapy approaches, including replacement gene therapy, optogenetics, addition of a growth factor, suppression gene therapy, and gene editing, have been proposed in attempts to treat various ophthalmologic conditions.