Safety and Effectiveness Study of the Zenflow Spring System

Prospective, multi-center, multinational, 2:1 randomized, single-blinded, controlled clinical trial of the Zenflow Spring System. Patients randomized to the treatment group will undergo Zenflow Spring placement. Patients randomized to the control group will undergo a Sham procedure. Patients and site personnel administering follow-up assessments will be blinded to the randomized treatment through completion of the 3-month follow-up visit. Once a patient has completed their 3-month follow-up assessments, they will be unblinded. Following unblinding, patients who received a Sham procedure may elect to receive treatment with the Zenflow Spring System or alternatively they may exit the study. The duration of study participation is 60 months for patients who receive a Spring Implant and 3 months for subjects in the Control Arm.