Thus, the increase of the endogenous NGF availability, following its intraocular (intravitreal or periocular) exogenous injection and/or topic instillation (Figure 2), is currently exploited as a safe, non-invasive approach to successfully counteract retina and even brain neurodegeneration underlying clinical signs of AMD and AD phenotypes (Tirassa et al., 2018; Mitra et al., 2019). Here, NGF is linked to Alzheimer disease.