BDNF and Optic neuropathy: Experimental studies in various disease models addressed mechanisms of action and indicated modulation of neurotrophic factors (IGF-1, BDNF, CNTF, FGF-2, TNF-α) and immunomodulators (IL-10, IL-6, COX-2, NF-κB) by electrical stimulation of the eye in optic neuropathies (Fu et al. 2018; Fu et al. 2015; Hanif et al. 2016; Yin et al. 2016).