5-Year Postoperative Outcomes of Patients Who Completed the CREST Study (CREST-XT)

FIVE-YEAR POSTOPERATIVE OUTCOMES IN PATIENTS WITH OPEN-ANGLE GLAUCOMA WHO UNDERWENT BIO-INTERVENTIONAL UVEOSCLERAL OUTFLOW ENHANCEMENT SURGERY: LONG-TERM OBSERVATIONAL FOLLOW-UP FROM THE CREST STUDY (THE CREST-XT STUDY)

This study is designed to collect clinical data at 3, 4, and 5 years postoperatively for participants who completed the CREST Study without having secondary IOP-lowering surgery in the study eye(s).

Study Overview

• Status: Enrolling by invitation
• Conditions: Open-angle Glaucoma (OAG)
• Intervention / Treatment: Procedure: CycloPen Micro-Interventional Cyclodialysis System; Procedure: CycloPen Micro-Interventional Cyclodialysis System Post Cataract

Detailed Description

This is a multicenter, prospective, observational study following eligible participants who completed the CREST Study. Participants who consent to participate will have clinical data gathered from annual ophthalmic examinations through 60 months after CycloPen System surgery for analysis of long-term outcomes. As an observational study, examinations at each visit are performed per the investigator's standard of care.

• Study Type: Observational
• Enrollment (Estimated): 250

Contacts and Locations

Study Locations

• United States
  • California
    • Newport Beach, California, United States, 92663
      • CREST-XT Site 05
  • Florida
    • Cape Coral, Florida, United States, 33904
      • CREST-XT Site 03
  • Georgia
    • Atlanta, Georgia, United States, 30342
      • CREST-XT Site 07
  • Maryland
    • Chevy Chase, Maryland, United States, 20815
      • CREST-XT Site 12
    • Rockville, Maryland, United States, 20852
      • CREST-XT Site 13
  • Nevada
    • Las Vegas, Nevada, United States, 89145
      • CREST-XT Site 16
  • New York
    • New York, New York, United States, 10034
      • CREST-XT Site 15
  • Pennsylvania
    • Fort Washington, Pennsylvania, United States, 19034
      • CREST-XT Site 01
  • Tennessee
    • Crossville, Tennessee, United States, 38555
      • CREST-XT Site 04
  • Utah
    • Salt Lake City, Utah, United States, 84132
      • CREST-XT Site 11

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Participants are undergoing treatment for glaucoma at medical clinics located in the United States

Description

Inclusion Criteria:

1. Diagnosis of open-angle glaucoma (OAG) in the study eye(s), including pigmentary and pseudoexfoliative glaucoma, at the time of CREST enrollment
2. Completed participation in CREST
3. Provide signed written consent using the Institutional Review Board (IRB)/Ethics Committee (EC) approved study-specific informed consent form (ICF)
4. Ability, comprehension, and willingness to follow study instructions

Exclusion Criteria:

1. Systemic disease that, in the opinion of the Investigator, would put participant's health at risk and/or prevent completion of required study visits
2. Early termination from CREST
3. Secondary surgical intervention for long-term IOP control in the study eye(s)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Bio-reinforced Cyclodialysis in conjunction with cataract surgery; Cataract surgery is performed, then followed by bio-reinforced cyclodialysis using the CycloPen Cyclodialysis System	Procedure: CycloPen Micro-Interventional Cyclodialysis System Post Cataract; After cataract surgery, the CycloPen Micro-Interventional Cyclodialysis System is used to create and cyclodialysis cleft and deliver allograft scleral tissue and/or viscous material to reinforce and maintain the cleft postoperatively.
Bio-reinforced Cyclodialysis alone; Bio-reinforced cyclodialysis is performed using the CycloPen Cyclodialysis System	Procedure: CycloPen Micro-Interventional Cyclodialysis System; The CycloPen Micro-Interventional Cyclodialysis System is used to create and cyclodialysis cleft and deliver allograft scleral tissue and/or viscous material to reinforce and maintain the cleft postoperatively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean change in intraocular pressure (IOP)	Mean change in intraocular pressure (IOP) measured using tonometry	From before bio-interventional cyclodialysis to 60 months after surgery

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean change in number of IOP-lowering medications used	Mean change in the number of IOP-lowering medications used	From before bio-interventional cyclodialysis to 60 months after surgery
Percent change in intraocular pressure (IOP)	Mean percent change in IOP in comparison with baseline (prior to surgery), while using the same or fewer IOP-lowering medications and without additional IOP-lowering surgical or laser procedures	From before bio-interventional cyclodialysis to 60 months after surgery
Percent of eyes with ≥ 20% decrease in intraocular pressure (IOP)	Proportion of eyes with postoperative IOP ≥ 20% lower than baseline (prior to surgery), while using the same or fewer IOP-lowering medications and without additional IOP-lowering surgical or laser procedures	From before bio-interventional cyclodialysis to 60 months after surgery

Collaborators and Investigators

• Sponsor: Iantrek, Inc.
• Investigators: Study Director: Tsontcho Ianchulev, MD, MPH, Iantrek, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): September 15, 2025
• Primary Completion (Estimated): December 1, 2030
• Study Completion (Estimated): December 1, 2030

Study Registration Dates

• First Submitted: December 29, 2025
• First Submitted That Met QC Criteria: March 14, 2026
• First Posted (Actual): March 18, 2026

Study Record Updates

• Last Update Posted (Actual): April 1, 2026
• Last Update Submitted That Met QC Criteria: March 26, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Bio-interventional cyclodialysis; AlloFlo; CycloPen
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Glaucoma; Glaucoma, Open-Angle
• Other Study ID Numbers: ITR-CYC-042

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No