NGF and optic nerve disorder: Neurotrophic factors including ciliary neurotrophic factor (CNTF) delivered by encapsulated cell therapy in an intravitreal implant [13, 14] and nerve growth factor (NGF) delivered as an eye drop have been tested in patients with glaucoma and other optic neuropathies with early signals of neuroenhancement measured by structure and function [11, 12, 15–18].