Subconjunctival Versus Direct Mitomycin C in Trabeculectomy

June 14, 2020 updated by: Jiun Do, University of California, San Diego

Subconjunctival Versus Direct Scleral Application of Mitomycin-C in Trabeculectomy

Trabeculectomy is routinely used as a surgical treatment for open angle glaucoma. Success of trabeculectomy is greatly augmented by the use of antimetabolites to inhibit wound healing, specifically Mitomycin C (MMC). MMC can be applied to the eye at various sites, concentrations and times. This study aims to compare the two application routes that are commonly employed: subconjunctival pre-operative injection and intraoperative direct scleral application in terms of IOP lowering effect, bleb appearance and complications.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Trabeculectomy is widely used as a surgical treatment of uncontrolled open glaucoma. Success of trabeculectomy at halting or slowing glaucoma progression primarily relies on the extent of conjunctival and sclera wound healing. The success rates of trabeculectomy increased dramatically with the introduction of anti-metabolites. For more than two decades mitomycin-c (MMC), a chemotherapeutic agent capable of decreasing fibroblast activity and modulating wound healing at the bleb, has been used with trabeculectomy. The complications of MMC are well known and several studies have described various methods of application based on exposure time, dose and surface area. Numerous retrospective and prospective studies have compared the efficacy of MMC applied beneath the conjunctival flap with soaked sponges versus intrascleral application. In 2008, Lee et al. first described an alternative route of application: subconjunctival injection of MMC directly into the intra-Tenon area. Seventy-six eyes with primary and secondary open angle glaucoma underwent trabeculectomy with this approach and were followed for one year post-operatively. Eighty-six percent of eyes achieved an IOP <21 mm Hg and 57% an IOP<14 mm Hg at one year without adjunctive drops. Transient complications included hyphema, bleb leak and choroidal detachment. The advantages of injected MMC are primarily in controlling the exact dosage and area of application and reduced surgical time. Lim et al. retrospectively reviewed the outcomes of trabeculectomy in 57 eyes using sponge application directly to the sclera versus intra-tenon injection. IOP was significantly lower in the injection group at 1 month, 1, 2, and 3 years. Trabeculectomy success (IOP<21mm Hg or IOP >20% below baseline without medications or additional surgery) was greater in the injection group at 3 years. The sponge group experienced more encapsulated blebs but complication rates were similar in both groups. To date, there have been no prospective studies comparing the IOP-lowering efficacy and safety of intra-tenon injection versus direct scleral application of MMC.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
100

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • medically uncontrolled glaucoma
  • healthy and freely mobile conjunctiva in superior bulbar region

Exclusion Criteria:

  • previous incisional glaucoma surgery
  • no light perception vision
  • pregnant or nursing women
  • iris neovascularization or proliferative retinopathy
  • iridocorneal endothelial syndrome
  • chronic or recurrent uveitis
  • steroid-induced glaucoma
  • pathologic myopia or refractive error less than -6.00 diopters
  • unwillingness or inability to give consent
  • inability to return for scheduled protocol visits

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: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Injection group
MMC delivered by preoperative subconjunctival injection
Drug: Mitomycin-C injection
MMC delivered by preoperative subconjunctival injection
Active Comparator: Sponge group
MMC delivered by intraoperative direct scleral application with impregnated cellulose sponges
Drug: Mitomycin-C sponge
MMC delivered by intraoperative direct scleral application with impregnated cellulose sponges

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Percentage of Participants Achieving Intraocular Pressure Reduction Thresholds
Time Frame: 6 months
Percentage of patients achieving at least a 30% mean intraocular pressure reductions from baseline and with an intraocular pressure <21 mm Hg. Subjects that met this criteria without the use of intraocular pressure lowering medications were classified as "Complete Success." Subjects that met this criteria but required the use of intraocular pressure lowering medications were classified as "Qualified Success." Subjects that failed to meet this criteria were classified as "Failure." Subjects that failed to meet this criteria and required additional glaucoma surgery were classified as "Complete Failure."
6 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Bleb Morphology
Time Frame: 6 months
Bleb morphology at 6 months was graded using Indiana Bleb Appearance Grading Scale. Bleb height was graded on a scale of 0 to 3 (0: flat bleb without visible elevation, 1: low bleb elevation, 2: moderate bleb elevation, 3: high bleb elevation). Bleb extent was graded on a scale of 0 to 3 (0: no visible bleb extent to less than 1 clock hour, 1: extent equal to or greater than 1 clock hour but less than 2 clock hours, 2: extent equal to or greater than 2 clock hours but less than 4 clock hours, 3: extent equal to or greater than 4 clock hours). Bleb vascularity was graded on a scale of 0 to 4 (0: avascular/white, 1: avascular/cystic, 2: mild vascularity, 3: moderate vascularity, 4: extensive vascularity). Scales are descriptive and do not necessarily represent better or worse outcomes.
6 months
Medications
Time Frame: 6 months
Number of intraocular pressure lowering medications used by the patient at follow up visit.
6 months
Visual Acuity
Time Frame: 6 months
Change in visual acuity from baseline
6 months
Number of Participants With Surgical Complications
Time Frame: 6 months
Number of eyes that experienced surgical complications following surgery
6 months
Number of Participants Requiring Additional Surgery
Time Frame: 6 months
Number of eyes requiring additional surgery from each group
6 months
Postoperative Interventions
Time Frame: 6 months
Mean number of postoperative interventions (needling, antifibrotic injections) performed in each group
6 months

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of California, San Diego

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jiun L Do, MD, PhD, UCSD
  • Principal Investigator: Robert N Weinreb, MD, UCSD
  • Principal Investigator: Benjamin Xu, MD, PhD, UCSD

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 23, 2016

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 14, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 14, 2019

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 15, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 15, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 20, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 2, 2020

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 14, 2020

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2020

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 151621

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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