Re-Trabeculectomy Versus Ahmed Glaucoma Valve Implantation in Secondary Surgical Management of Patients With Refractory Glaucoma

July 3, 2012 updated by: Nariman Nassiri, Vanak Eye Surgery Center

Re-Trabeculectomy Versus Ahmed Glaucoma Valve Implantation in Secondary Surgical Management of Patients With Refractory Primary Open Angle Glaucoma: a Three-year Comparative Study

The purpose of this study is to compare three-year outcomes of re-trabeculectomy with those of Ahmed glaucoma valve implantation in secondary surgical management of patients with primary open angle glaucoma (POAG) and a history of previous failed trabeculectomy.

Study Overview

Detailed Description

Currently, lowering intraocular pressure (IOP) is the only treatment modality to prevent or slow progression of glaucomatous optic nerve damage. Incisional procedures are indicated when medical therapy and/or laser procedures cannot adequately reduce IOP. Trabeculectomy is the most common glaucoma incisional procedure globally. On the other hand, glaucoma drainage devices that have been historically reserved for cases of glaucoma deemed at high risk of failure have increasingly gained popularity particularly in eyes with previous history of glaucoma surgery.

There is still no agreement on the appropriate surgical procedure in those with prior glaucoma surgery. The five-year tube versus trabeculectomy (TVT) study, which evaluated the efficacy and safety of Baerveldt glaucoma implant versus trabeculectomy, showed that both surgical procedures had similar IOP reduction and use of anti-glaucoma medication; tube shunt surgery had a higher success rate than trabeculectomy with mitomycin C (MMC); the trabeculectomy/MMC had higher incidence of early postoperative complications compared to tube shunt surgery; and rates of late postoperative complications, reoperation for complications, and cataract extraction were comparable in both treatment groups.

In this study, the investigators compared three-year outcomes of re-trabeculectomy with those of Ahmed glaucoma valve implantation in secondary surgical management of patients with primary open angle glaucoma and a previous history of failed trabeculectomy.

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

      • Tehran, Iran, Islamic Republic of
        • Imam Hossein medical center
      • Tehran, Iran, Islamic Republic of
        • Negah Eye Hospital
      • Tehran, Iran, Islamic Republic of
        • Vanak Eye Surgery Center

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

38 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Patients with refractory primary open angle glaucoma and a history of failed trabeculectomy with mitomycin C (MMC).

Description

Inclusion Criteria:

  • Uncontrolled glaucoma defined as (1) IOP not achieving previously assigned target pressure despite prior trabeculectomy and use of maximally tolerated anti-glaucoma medication; and (2) recent progression of the disease based on glaucomatous changes in optic disc appearance and/or worsening of the visual field exam.
  • In the case of two eligible eyes, only the first eye being operated on was enrolled

Exclusion Criteria:

  • Younger than 40 years old
  • Visual acuity of no light perception
  • Lens opacity
  • Elevated IOP associated with silicone oil
  • Prior ocular surgeries other than one trabeculectomy with MMC
  • Previous cyclodestructive treatment
  • Increased risk of endophthalmitis
  • Posterior segment disorders
  • Pre-existing ocular comorbidities (e.g. pterygium,phacodonesis,corneal opacity, or corneal endothelial dystrophies)

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

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Ahmed glaucoma implant
In the Ahmed implant group, the tube shunts used were the valved 184-mm2 surface area (Model FP7; New World Medical, Inc, Rancho Cucamonga, California, USA). In the Trabeculectomy group, a routine trabeculectomy surgery was performed.
Trabeculectomy with mitomycin C (MMC)
In the Ahmed implant group, the tube shunts used were the valved 184-mm2 surface area (Model FP7; New World Medical, Inc, Rancho Cucamonga, California, USA). In the Trabeculectomy group, a routine trabeculectomy surgery was performed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in target intraocular pressure (IOP)
Time Frame: day 1, week 1, months 1,3,6,9,12,18,24,30,36
All patients had a target IOP that had been assigned for them by the same surgeon prior to their initial failed trabeculectomy/MMC. The routine practice of the surgeon has been to set target IOP based on the Best Practice Treatment Algorithm for POAG. This was based on at least 25% reduction in baseline IOP. Target IOP needs constant reevaluation during the follow-up based on disease progression. In our study, success and failure were considered to be assessed based on change in the target pressure.
day 1, week 1, months 1,3,6,9,12,18,24,30,36

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of anit-glaucoma medications
Time Frame: day 1, week 1, months 1,3,6,9,12,18,24,30,36
day 1, week 1, months 1,3,6,9,12,18,24,30,36
Visual Acuity
Time Frame: day 1, week 1, months 1,3,6,9,12,18,24,30,36
day 1, week 1, months 1,3,6,9,12,18,24,30,36
Mean deviation of visual field exam
Time Frame: Months 6,12,18,24,30,36
Only visual field results where consecutive field tests did not show an improvement of 2 dB or more in the mean deviation (MD) over the baseline reading were included as we considered the phenomenon of learning effect in our analysis.
Months 6,12,18,24,30,36
Surgical Success
Time Frame: day 1, week 1, months 1,3,6,9,12,18,24,30,36
Surgical failure was defined as persistent IOP of more than target pressure on maximally tolerated medications or IOP less than 6 mm Hg on two consecutive visits, phthisis bulbi, reduction of vision to no light perception, removal of the shunt implant, reoperation for glaucoma, or any devastating intraoperative and postoperative complications.
day 1, week 1, months 1,3,6,9,12,18,24,30,36

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Nariman Nassiri, MD, MPH, Vanak Eye Surgery Center

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

December 1, 2007

Primary Completion (Actual)

January 1, 2012

Study Completion (Actual)

January 1, 2012

Study Registration Dates

First Submitted

June 29, 2012

First Submitted That Met QC Criteria

July 3, 2012

First Posted (Estimate)

July 4, 2012

Study Record Updates

Last Update Posted (Estimate)

July 4, 2012

Last Update Submitted That Met QC Criteria

July 3, 2012

Last Verified

June 1, 2012

More Information

Terms related to this study

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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