RPE65 and respiratory distress syndrome in premature infants: Following the successful market launch of a subretinal gene augmentation therapy for IRDs caused by biallelic RPE65 mutations (voretigene neparvovec, Luxturna®, Spark Therapeutics, Inc.), several studies are exploring viral vector-based approaches to deliver functional gene copies for autosomal recessive or X-chromosomal forms of IRDs and IONs.