This study focused on the comparison of transduction efficiency of the three natural AAV serotypes AAV5, AAV8, and AAV9 and the synthetic serotype AAV2.7m8, expressing GFP in two models: HEK293 and ARPE-19, the more relevant retinal pigment epithelium cell line, which will be used for in vitro potency tests of the newly developed gene replacement therapies for the treatment of IRDs, including RDH12-associated retinopathy. This evidence concerns the gene RDH12 and respiratory distress syndrome in premature infants.