Glaucoma involves transneuronal degeneration of the posterior structures along the central visual pathway, as the neurotrophic factor like brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CTNF), and metabolites like choline plays a significant part in it.[34] The volume of primary visual cortex and visual pathway including LGN, V1, lingual gyrus and calcarine fissure decreases indicating the atrophy of these structures. This evidence concerns the gene LTB and glaucoma.