Gene therapy is a medical approach that aims at counteracting the pathological effects of gene mutations that cause inherited disorders. A gene is a portion of DNA that contains the information that the cells need to produce a protein with a given function. If a gene is defective, the cells cannot produce the corresponding protein and will lack a function. The more important the function, the faster the onset and the more serious the disease. Gene therapy aims at inserting in the patients’ cells therapeutic exogenous DNA able to do what the patient’s defective DNA cannot do, hence repristinating the lacking protein and its function.
Inherited retinal diseases have since ever been uncurable causes of blindness and low vision in children, teenagers and adults, and the new tangible hope of treatment given by gene therapy for this type of diseases has radically changed perspectives in ophthalmology. The eye is an ideal compartment for the application of this technique and the first FDA approved gene therapy ever has been that approved in 2017 for the forms of Leber Congenital Amaurosis and retinitis pigmentosa caused by homozygous autologous recessive mutations of the RPE65 gene – a gene essential for the correct functioning of the visual cycle.
The advent of gene therapy in real clinical practice represents a milestone in ophthalmology and medicine and opens the door to a new era of therapeutic potentials aimed at defeating pathologies that are up to date uncurable. It is important to mention that gene therapy can also be employed in the treatment of chronic diseases, such as for example age-related macular degeneration (AMD), by inserting in the patients’ retinal cells the information needed to produce a therapeutic molecule, such as, in the case of AMD, anti-VEGF.