Target-derived survival factor for peripheral sensory sympathetic neurons.Defects in NTF4 may be associated with susceptibility to primary open angle glaucoma type 1O (GLC1O). A form of primary open angle glaucoma (POAG). POAG is characterized by a specific pattern of optic nerve and visual field defects. The angle of the anterior chamber of the eye is open, and usually the intraocular pressure is increased. The disease is asymptomatic until the late stages, by which time significant and irreversible optic nerve damage has already taken place.