Primary Tube Versus Trabeculectomy Study

October 18, 2022 updated by: Steven J. Gedde, University of Miami
The purpose of the Primary Tube Versus Trabeculectomy (PTVT) Study is to compare the long-term safety and efficacy of nonvalved tube shunt surgery to trabeculectomy with mitomycin C in eyes that have not had previous ocular surgery.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

242

Phase

  • Phase 4

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

  • Canada
      • Toronto, Canada
        • University of Toronto
  • United Kingdom
      • London, United Kingdom
        • St. Thomas' Hospital
      • London, United Kingdom
        • Moorfields Eye Hospital
      • Sidcup, United Kingdom
        • Queen Mary's Sidcup Hospital
  • United States
    • California
      • Sacramento, California, United States, 95817
        • University of California Davis Medical Center
    • Florida
      • Gainesville, Florida, United States, 32610
        • University of Florida
      • Miami, Florida, United States, 33136
        • Bascom Palmer Eye Institute
    • Maryland
      • Baltimore, Maryland, United States, 21290
        • Johns Hopkins
    • Missouri
      • Saint Louis, Missouri, United States, 63104
        • St. Louis University
    • New York
      • New York, New York, United States, 10003
        • New York Eye and Ear Infirmary
    • Ohio
      • Cincinnati, Ohio, United States, 45242
        • Cincinnati Eye Institute
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73104
        • University of Oklahoma
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • University of Pennsylvania
    • Texas
      • Dallas, Texas, United States, 75231
        • Glaucoma Associates of Texas
      • Houston, Texas, United States, 77030
        • University of Texas, Houston
    • Virginia
      • Charlottesville, Virginia, United States, 22908
        • University of Virginia

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

18 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Age 18-85 years
  • Glaucoma that is inadequately controlled on tolerated medical therapy with Intraocular Pressure (IOP) greater than or equal to 18 mm Hg and less than or equal to 40 mm Hg
  • No previous incisional ocular surgery

Exclusion Criteria:

  • Unwilling or unable to give consent, unwilling to accept randomization, or unable to return for scheduled protocol visits
  • Pregnant or nursing women
  • No light perception vision
  • Active iris neovascularization or active proliferative retinopathy
  • Iridocorneal endothelial syndrome
  • Epithelial or fibrous ingrowth
  • Chronic or recurrent uveitis
  • Steroid-induced glaucoma
  • Severe posterior blepharitis
  • Unwilling to discontinue contact lens use after surgery
  • Previous cyclodestructive procedure
  • Conjunctival scarring from prior ocular trauma or cicatrizing disease precluding a superior trabeculectomy
  • Functionally significant cataract
  • Need for glaucoma surgery combined with other ocular procedures or anticipated need for additional ocular surgery

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tube shunt surgery group
Participants in this group will receive a tube shunt surgery (Baerveldt Glaucoma implant).
Procedure: Tube shunt surgery
The procedure involves implantation of a Baerveldt consisting of a tube that is connected to an end plate. The tube is inserted into the anterior chamber and shunts aqueous humor to the end plate located in the equatorial region of the eye. The aqueous humor is then absorbed by the tissues around the eye.
Other Names:
  • Baerveldt glaucoma implant
Experimental: Trabeculectomy with Mitomycin C
Participants in this group will receive a Trabeculectomy surgery with Mitomycin C
Procedure: Trabeculectomy
The procedure involves removal of a small portion of trabecular meshwork and adjacent tissue under a partial thickness scleral flap. Aqueous humor drains into the subconjunctival space producing a filtering bleb. The aqueous humor then diffuse out of the bleb.
Drug: Mitomycin C
A fluid retaining sponge soaked in 0.4 mg/ml Mitomycin C will be applied in the region of Trabeculectomy site for about 2 minutes

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With Surgical Failure
Time Frame: Up to 5 years

Surgical failure is defined as:

  1. Inadequate Intraocular Pressure (IOP) Reduction (IOP > 21 mmHg or reduced < 20% below baseline on 2 consecutive follow-up visits after 3 months)
  2. Reoperation for glaucoma
  3. Persistent hypotony (IOP ≤ 5 mmHg on 2 consecutive visits after 3 months)
  4. Loss of light perception vision
Up to 5 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Intraocular Pressure
Time Frame: At baseline, At 1 year, At 18 months, At 2 years, At 3 years, At 4 years, At 5 years
Intraocular pressure will be reported in mmHg and measured using Goldmann applanation tonometry or a Tono-Pen.
At baseline, At 1 year, At 18 months, At 2 years, At 3 years, At 4 years, At 5 years
Number of Participants With Reported Postoperative Complications
Time Frame: Up to 5 years
Number of participants with early and late postoperative complications will be reported as per treating physician assessment
Up to 5 years
Visual Acuity Using a Snellen Chart
Time Frame: At Baseline, At 5 years
Visual acuity will be measured using a Snellen chart on logMAR (Logarithm of Minimal Angle of Resolution) scale. Letter-by letter results calculated the visual performance score for each chart read. logMAR scores closer to zero, or below zero, indicate a better visual acuity. A logMAR visual performance score of 0.0 is equivalent to Snellen visual acuity of 20/20.
At Baseline, At 5 years
Visual Acuity as Measured Using EDTRS Chart
Time Frame: At baseline, At 5 years
Visual acuity will be reported as the number of correctly identified letters on the Early Treatment Diabetic Retinopathy Study (EDTRS) chart. Total score ranges from 0-100 with the higher score indicating better visual acuity.
At baseline, At 5 years
Visual Field
Time Frame: Up to 5 years
Visual fields will be measured using standard automated perimetry.
Up to 5 years
Reoperation for Glaucoma
Time Frame: Up to 5 years
The number of participants requiring reoperation for glaucoma will be reported
Up to 5 years
Number of Glaucoma Medications
Time Frame: At Baseline, At 1 year, At 18 months, At 2 years, At 3 years, At 4 years, At 5 years
The need for supplemental glaucoma medications will be reported as the number of glaucoma medications used
At Baseline, At 1 year, At 18 months, At 2 years, At 3 years, At 4 years, At 5 years

Collaborators and Investigators

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

Sponsor

University of Miami

Collaborators

National Eye Institute (NEI)
Abbott Medical Optics
Research to Prevent Blindness

Investigators

  • Study Chair: Steven J Gedde, MD, Bascom Palmer Eye Institute
  • Study Chair: Dale K Heuer, MD, Medical College of Wisconsin
  • Study Chair: Richard K Parrish, MD, Bascom Palmer Eye Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

April 1, 2008

Primary Completion (Actual)

April 1, 2021

Study Completion (Actual)

April 1, 2021

Study Registration Dates

First Submitted

April 23, 2008

First Submitted That Met QC Criteria

April 23, 2008

First Posted (Estimate)

April 24, 2008

Study Record Updates

Last Update Posted (Actual)

October 19, 2022

Last Update Submitted That Met QC Criteria

October 18, 2022

Last Verified

October 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 20071037
  • EY014801 (Other Grant/Funding Number: National Eye Institute)

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

Yes

Studies a U.S. FDA-regulated device product

No

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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