• Participant must be medically able to undergo the testing required in the schedule of events (SOE).

• Participant's clinical diagnosis must be consistent with glaucoma characterized by the following features: Mean deviation (MD) of -3 to -20 dB on Humphrey Visual Field 24-2 testing and two visual field tests of adequate quality with a maximum VFI variability of ± 10%

• Residual visual field preservation including best-corrected visual acuity (BCVA) better than 20/200 in either eye.

• Participant's eye pressure must be clinically stable, with IOP \<21.

• If a participant has two eyes meeting study criteria, the worse eye as determined by visual field index (VFI) or patient preference, will be deemed includable. If both eyes qualify and have the same VFI, a randomization procedure will assign one eye to the study.

• Participant must understand and sign the informed consent. If the participant's vision is impaired to the point where he/she cannot read the informed consent document, the document will be read to the participant in its entirety.

• Females of childbearing potential must agree to use an effective form of birth control.

• Participant must be determined by the presurgical anesthesia or medical team to be fit for ophthalmic surgery for the NT-501 ECT implant insertion.