Ciliary Neurotrophic Factor (CNTF) has been demonstrated in multiple preclinical models to enhance survival and regeneration of retinal ganglion cells, the retinal neurons injured in diseases like ischemic optic neuropathy/optic nerve stroke. We hypothesize that CNTF delivery to the human eye will provide neuroprotection (prevent loss of vision) and neuroenhancement (improve vision indices) in ischemic optic neuropathy. Patients in the trial will receive an NT-501 CNTF implant (made by Neurotech) into one eye, and will be carefully followed to evaluate safety and efficacy.

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.