Trabectome Versus Trabeculectomy With Mitomycin C in Patients With Open Angle Glaucoma

Prospective Randomized Controlled Trial of Trabectome Versus Trabeculectomy With Mitomycin C in Patients With Open Angle Glaucoma

The purpose of this study is to compare the efficacy and safety of Trabectome versus Trabeculectomy with adjunctive Mitomycin C, combined with cataract surgery, in patients with open angle glaucoma.

Study Overview

• Status: Terminated
• Conditions: Open Angle Glaucoma
• Intervention / Treatment: Procedure: Trabectome-IOL; Procedure: Trab-IOL

Detailed Description

Background: Trabeculectomy with adjunctive use of Mitomycin C (Trab MMC) is the standard incisional procedure to lower intraocular pressure (IOP) in adults with open angle glaucoma (OAG). Trab MMC has been shown to effectively lower IOP, however, it can be associated with a number of serious complications, such as hypotony maculopathy, choroidal effusion or hemorrhage, and endophthalmitis, as well as less serious complications that may affect vision related quality of life such as bleb dysesthesia.

A newer technology, referred to as the Trabectome (NeoMedix Corp., San Juan Capistrano, CA), removes an arc of trabecular meshwork and inner wall of Schlemm's canal with microcautery and appears to lower IOP effectively with fewer and less serious complications than Trab MMC. However, more studies are needed to determine the long term safety and efficacy of this relatively new procedure.

In addition, for OAG patients with visually significant cataracts, either Trab MMC or Trabectome can be combined with cataract surgery.

Study Objective: To compare the efficacy and safety of Trabectome versus Trab MMC, in combination with cataract extraction by phacoemulsification and intraocular lens implant, for control of IOP in OAG, including pseudoexfoliative glaucoma.

Methods: Single center, single surgeon, prospective randomized controlled trial. A total of 52 eligible participants, 26 per study arm would need to be recruited for 90% power. One eye per study patient will be enrolled and randomized to Trabectome combined with cataract surgery (Trabectome-IOL) or Trab MMC combined with cataract surgery (Trab-IOL).

Postoperative visits will take place at the discretion of the surgeon but will include at least visits at day 1, week 1, and months 1, 3, 6, and 12. Postoperative glaucoma medications will be added in a stepped regimen as appropriate, along with additional laser or surgical procedures if needed.

Current Study Status: The clinical trial was terminated early due to slow recruitment and clearer indications for each technique over time leading to lack of clinical equipoise essential for patient randomization/recruitment. This had been discussed and agreed upon with our data safety monitoring board. A total of 19 participants were recruited with followup to one year. Study analysis is pending.

• Study Type: Interventional
• Enrollment (Actual): 19
• Phase: Phase 3

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada, T5H 3V9
      • Royal Alexandra Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Age 40-85 years
2. Open angle glaucoma (including pseudo exfoliative glaucoma)
3. Open angles (≥ Shaffer grade II)
4. Inadequately controlled IOP requiring surgical intervention
5. Visually significant cataract
6. Willing to complete quality of life questionnaires
7. Capable of informed consent and available for at least 1 year follow-up

Exclusion Criteria:

1. Any form of angle closure glaucoma
2. Secondary open angle glaucomas
3. Absence of clear angle landmarks on gonioscopy
4. Other ocular disease that may affect assessments of visual acuity, visual field, or accurate tonometry
5. Previous angle surgery or filtering procedure
6. Steroid use within the preceding 3 months
7. Presence of significant co-morbidities

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Trabectome-IOL; Combined Trabectome and cataract extraction with intraocular lens insertion	Procedure: Trabectome-IOL; Trabectome removes an arc of trabecular meshwork and inner wall of Schlemm's canal to enhance aqueous outflow through natural drainage pathways. Trabectome will be done first, followed by cataract surgery because Trabectome requires a clear view through the cornea using a goniolens, and this view may be compromised after cataract surgery.
Active Comparator: Trab-IOL; Combined Trabeculetomy with Mitomycin C and cataract extraction with intraocular lens insertion	Procedure: Trab-IOL; Trabeculectomy bypasses the normal aqueous outflow channels of the eye and creates an external filtration pathway (called a filtering bleb) for aqueous to drain and be reabsorbed back into the circulation. Mitomycin C is an agent used during this procedure to decrease scar formation around the new passage. Cataract surgery will be done first, followed by Trabeculectomy with Mitomycin C.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Mean IOP at 6 months	6 months
Surgical complication rates	intraoperative and postoperative up to 12 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Visual acuity	12 months
Mean difference in IOP from baseline to 6 months	6 months
Mean IOP at 12 months	12 months
Quality of life measures	preoperative and postoperative at 6 and 12 months
Mean number of glaucoma medications	12 months
Need for additional laser (excluding suture lysis) and surgical interventions	12 months

Collaborators and Investigators

• Sponsor: University of Alberta
• Investigators: Principal Investigator: Karim F Damji, MD FRCSC MBA, University of Alberta

Publications and helpful links

General Publications

• Hu K, Shah A, Virgili G, Bunce C, Gazzard G. Ab interno trabecular bypass surgery with Trabectome for open-angle glaucoma. Cochrane Database Syst Rev. 2021 Feb 4;2(2):CD011693. doi: 10.1002/14651858.CD011693.pub3.
• Hu K, Gazzard G, Bunce C, Wormald R. Ab interno trabecular bypass surgery with Trabectome for open angle glaucoma. Cochrane Database Syst Rev. 2016 Aug 15;(8):CD011693. doi: 10.1002/14651858.CD011693.pub2.

Study record dates

Study Major Dates

• Study Start: November 1, 2009
• Primary Completion (Actual): April 1, 2015
• Study Completion (Actual): October 1, 2015

Study Registration Dates

• First Submitted: May 11, 2009
• First Submitted That Met QC Criteria: May 12, 2009
• First Posted (Estimate): May 13, 2009

Study Record Updates

• Last Update Posted (Estimate): February 25, 2016
• Last Update Submitted That Met QC Criteria: February 23, 2016
• Last Verified: February 1, 2016

More Information

Terms related to this study

• Keywords: cataract; trabeculectomy; open angle glaucoma; trabectome
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Glaucoma; Glaucoma, Open-Angle
• Other Study ID Numbers: UAKD-001

Plan for Individual participant data (IPD)

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