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

Completed

• Conditions: Refractory Primary Open Angle Glaucoma
• Interventions: Procedure: Implantation of Ahmed glaucoma tube shunt, and Trabeculectomy with MMC

• Registration Number: NCT01633775
• Lead Sponsor: Vanak Eye Surgery Center

Brief Summary

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.

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 Timeline

• Study Start: 2007-12
• Primary Completion: 2012-01
• Study Completion: 2012-01
• Status Verified: 2012-06
• Study First Submitted: 2012-06-29
• Study First Submitted QC: 2012-07-03
• Last Update Submitted: 2012-07-03
• Study First Posted: 2012-07-04
• Last Update Posted: 2012-07-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 100

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 & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Trabeculectomy with mitomycin C (MMC)	Implantation of Ahmed glaucoma tube shunt, and Trabeculectomy with MMC	-
Ahmed glaucoma implant	Implantation of Ahmed glaucoma tube shunt, and Trabeculectomy with MMC	-

Primary Outcome Measures

Name	Time	Method
Change in target intraocular pressure (IOP)	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.

Secondary Outcome Measures

Name	Time	Method
Visual Acuity	day 1, week 1, months 1,3,6,9,12,18,24,30,36
Mean deviation of visual field exam	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.
Number of anit-glaucoma medications	day 1, week 1, months 1,3,6,9,12,18,24,30,36
Surgical Success	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.

Trial Locations

Locations (3)

Imam Hossein Medical Center; 🇮🇷 Tehran, Iran, Islamic Republic of

Negah Eye Hospital; 🇮🇷 Tehran, Iran, Islamic Republic of

Vanak Eye Surgery Center; 🇮🇷 Tehran, Iran, Islamic Republic of