Ciliary Neurotrophic Factor (CNTF) has been demonstrated in multiple pre-clinical models to enhance survival and regeneration of retinal ganglion cells, the retinal neurons injured in diseases like glaucoma. We hypothesize that CNTF delivery to the human eye will provide neuroprotection (prevent loss of vision) and neuroenhancement (improve vision indices) in glaucoma. 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:

• 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 glaucoma characterized by (a) clinical evidence of progressive RGC dysfunction and degeneration using both visual field and at least one structural modality; (b) residual visual field preservation including best-corrected visual acuity (BCVA) better than 20/100; (c) failure to contain glaucomatous progression with maximally tolerated reduction of intraocular pressure (IOP), OR visual field defect affecting fixation, but not reducing BCVA below 20/100.

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.