Figure 1.

Illustration of most commonly used AAV delivery routes. For CNS diseases (e.g., Parkinson, Alzheimer, Huntington), the intraparenchymal administration of viral particles is by far the strategy most commonly used, followed by intra-CSF administration (intraventricular, intracisternal, and intrathecal). Several ongoing gene therapy studies are focused on targeting blindness and deafness disorders, and, in these scenarios, eye delivery (e.g., subretinal, intravitreal, intracameral, etc.) and ear delivery (e.g., cochleostomy or RWM) have proven preclinical success.