NT-501 CNTF Implant for Ischemic Optic Neuropathy: Safety, Neuroprotection and Neuroenhancement

Inclusion Criteria: * age 40 years or older * must understand and sign the informed consent * must be medically able to undergo ophthalmic surgery for the NT-501 device insertion and possible removal, as well as the testing required. * diagnosis of ischemic optic neuropathy characterized by (a) non-arteritic subtype, including a normal ESR and CRP; (b) syndrome of acute unilateral visual loss with documented optic nerve head edema but without significant pain; (c) a relative afferent papillary defect in the affected eye, and a decrease of best-corrected visual acuity to 20/40 or worse in the affected eye, and detectable loss on visual field testing consistent with nerve fiber visual field defect but retaining measurable residual visual field preservation. Exclusion Criteria: * other corneal, lens, optic nerve or retinal disease causing vision loss, * blind in one eye * requirement of acyclovir and/or related products during study * receiving systemic steroids or other immunosuppressive medications. * pregnant or lactating. * considered immunodeficient or has a known history of human immunodeficiency virus (HIV) * on chemotherapy, or a history of malignancy, UNLESS it was treated successfully 2 years prior to inclusion in the trial.