A Real-World Evidence Study of Goniotomy With the C-REX™ Instrument in Patients With Primary Open Angle Glaucoma (CIRCLE)

July 18, 2026 updated by: Iantrek, Inc.

An Observational Real-World Evidence Study of Ab-Interno Goniotomy Performed Using the C-Rex Instrument in Patients With Primary Open Angle Glaucoma

This study enrolls adults with primary open angle glaucoma (POAG) who underwent goniotomy intraocular pressure (IOP)-lowering surgery with the C-Rex Instrument. Patients are consented prior to surgery and followed for 12 months postoperatively. Data regarding IOP, use of glaucoma medications, and any device-related complications are collected during the study time period.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

This a multicenter, observational real-world evidence study of eligible adults with primary open angle glaucoma (POAG) in whom ab-interno goniotomy surgery with the C-Rex Instrument was performed.

Data is collected from the preoperative visit(s) that directly preceded the surgery, the surgical procedure, and post-surgical visits through 12 months postoperatively.

Specific data collected includes C-Rex Instrument goniotomy surgical details, preoperative and postoperative IOP and use of ocular hypotensive medications, and device-related safety events.

Study Type

Observational

Enrollment (Actual)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Florida
      • Cape Coral, Florida, United States, 33904
        • CIRCLE Site 32
      • DeLand, Florida, United States, 32720
        • CIRCLE Site 10
    • Georgia
      • Atlanta, Georgia, United States, 30342
        • CIRCLE Site 07
    • New York
      • Brentwood, New York, United States, 11717
        • CIRCLE Site 30
      • Rockville Centre, New York, United States, 11570
        • CIRCLE Site 31
    • Tennessee
      • Crossville, Tennessee, United States, 38555
        • CIRCLE Site 04

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Eligible participants who underwent IOP-lowering surgical procedures using the C-Rex Instrument to perform ab-interno goniotomy

Description

Inclusion Criteria:

  • Primary open angle glaucoma
  • Goniotomy surgery performed using the C-Rex Instrument

Exclusion Criteria:

  • History of intraocular surgery within 8 weeks prior to C-Rex surgery
  • Preoperative IOP higher than 33 mmHg
  • Presence of a glaucoma type other than POAG
  • Presence of clinically significant intraocular pathology other than cataract or glaucoma

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
C-Rex surgery - combination
C-Rex surgery combined with cataract extraction/intraocular lens (IOL) implantation
Device: C-Rex Instrument
The C-Rex Instrument is a manual ophthalmic surgical instrument used for ab interno goniotomy and inner wall trabeculotomy.
C-Rex surgery - standalone
C-Rex surgery as a standalone intervention
Device: C-Rex Instrument
The C-Rex Instrument is a manual ophthalmic surgical instrument used for ab interno goniotomy and inner wall trabeculotomy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent of eyes with intraocular pressure (IOP)reduction ≥20%in comparison with baseline.
Time Frame: 12 month postoperative
Intraocular pressure (IOP) is at least 20% lower than before surgery without additional ocular hypotensive medications or IOP-lowering surgery.
12 month postoperative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Iantrek, Inc.

Investigators

  • Study Director: Tsontcho Ianchulev, MD, MPH, CMO

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 14, 2024

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

September 24, 2024

First Submitted That Met QC Criteria

September 24, 2024

First Posted (Actual)

September 26, 2024

Study Record Updates

Last Update Posted (Actual)

July 21, 2026

Last Update Submitted That Met QC Criteria

July 18, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ITR-GON-041

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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