Refractory GlaucomaAGVNCT07003685
Efficacy and Safety of Posterior Chamber Glaucoma Drainage Device
A study testing GDD in posterior chamber and GDD in aterior chamber in people with Refractory Glaucoma, run by Eye Hospital of Ho Chi Minh City at 1 site in Vietnam.
Trial summary
The goal of this clinical trial is to evaluate the efficacy and safety of Ahmed glaucoma valve (AGV) implantation in the posterior chamber (ciliary sulcus) compared with the traditional anterior chamber placement in patients with refractory pseudophakic glaucoma, who are adults (>18 years), have undergone cataract… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Refractory Glaucoma
- What is being tested?
- GDD in posterior chamber and GDD in aterior chamber
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteVietnam
- Study dates
- 2 Aug 2024to 2 Aug 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age over 18 years.
- Diagnosis of refractory glaucoma (uncontrolled intraocular pressure despite maximal tolerated antiglaucoma medications).
- History of cataract extraction with intraocular lens implantation (pseudophakia).
- Agreement to participate in the study and ability to comply with outpatient follow-up requirements
Who cannot join
- Presence of corneal opacities that preclude accurate endothelial assessment.
- Co-existing corneal diseases that could affect endothelial cell status (e.g., Fuchs' dystrophy, corneal edema).
- Single-eye (monocular) status.
- Systemic medical conditions affecting coagulation or carrying increased surgical risk (e.g., uncontrolled diabetes, bleeding disorders)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Vietnam1 site
Hochiminh city Eye Hospital
Ho Chi Minh City, Ho Chi Minh, 700000
About this study
Official title: Efficacy and Safety of Posterior Chamber Glaucoma Drainage Device in Refractory Pseudophakic Glaucoma Patients
The goal of this clinical trial is to evaluate the efficacy and safety of Ahmed glaucoma valve (AGV) implantation in the posterior chamber (ciliary sulcus) compared with the traditional anterior chamber placement in patients with refractory pseudophakic glaucoma, who are adults (>18 years), have undergone cataract surgery with intraocular lens implantation, and are unresponsive to maximal medical therapy.
The main questions it aims to answer are:
Read more
Does posterior chamber AGV implantation effectively lower intraocular pressure (IOP) compared to anterior chamber implantation? Does posterior chamber AGV implantation result in less corneal endothelial cell loss and lower rates of postoperative complications compared to anterior chamber implantation?
Researchers will compare the two groups:
Intervention group: AGV implantation in the posterior chamber (ciliary sulcus) Control group: AGV implantation in the anterior chamber
Participants will:
Undergo a baseline evaluation, including ocular examination, IOP measurement, corneal endothelial cell density (ECD) and variability, visual field testing, and optic nerve imaging.
Be randomized into two groups based on a computer-generated randomization method.
Receive either posterior chamber or anterior chamber AGV implantation. Be followed postoperatively at specified intervals (1 day, 1 week, 1 month, 3 months, 6 months, 12 months) for IOP, use of glaucoma medications, visual acuity (Snellen, logMAR), corneal ECD, and endothelial cell variability (CV).
Undergo regular assessments for postoperative complications such as hypotony, choroidal detachment, hyphema, infection, and device-related issues.
Provide informed consent after explanation of potential risks and benefits of the procedure.
This study will use a prospective, randomized controlled clinical trial design, enrolling at least 29 eyes in each group, conducted at the Glaucoma Department of Ho Chi Minh City Eye Hospital from March 2024 to March 2027
Read the detailed description
- Background and Rationale Refractory glaucoma in pseudophakic eyes presents a significant clinical challenge due to its resistance to maximal medical therapy and often poor response to conventional filtering surgeries. In these patients, the implantation of a glaucoma drainage device (GDD), such as the Ahmed glaucoma valve (AGV), has emerged as a viable therapeutic strategy. Traditionally, GDDs are inserted with the tube placed into the anterior chamber (AC). However, anterior chamber placement may be associated with long-term complications, such as corneal endothelial decompensation, synechiae, iris chafing, and chronic inflammation. The posterior chamber, specifically the ciliary sulcus, offers an alternative site for tube placement in pseudophakic eyes where the natural lens has already been removed. The sulcus location provides a deeper site for the tube, reducing the risk of contact with the corneal endothelium. Preliminary evidence and retrospective series suggest that sulcus placement can achieve comparable IOP-lowering efficacy while minimizing endothelial cell loss. However, to date, there is a lack of high-quality randomized controlled trials that rigorously compare the safety and efficacy outcomes of anterior vs posterior chamber tube placement in pseudophakic patients. This study is designed to address this gap in the literature by evaluating Ahmed glaucoma valve implantation with tube placement in the posterior chamber (ciliary sulcus) compared with standard anterior chamber placement in patients with refractory pseudophakic glaucoma.
- Objectives Primary Objective To evaluate and compare the intraocular pressure (IOP) reduction at 12 months following AGV implantation in the posterior chamber (ciliary sulcus) versus anterior chamber placement in eyes with refractory pseudophakic glaucoma. Secondary Objectives To assess the difference in corneal endothelial cell loss between the two groups. To compare the number of glaucoma medications required postoperatively. To evaluate the incidence of postoperative complications in both surgical groups. To determine the cumulative surgical success rates (complete and qualified success).
- Study Design This is a prospective, randomized, controlled, interventional clinical trial conducted at the Glaucoma Department of Ho Chi Minh City Eye Hospital. The study will enroll a total of 58 eyes (29 eyes per group), assigned to either anterior or posterior chamber AGV implantation via computer-generated randomization. The study period spans from March 2024 to August 2027, including a 12-month follow-up for each participant.
- Participants Eligible participants are adults aged ≥18 years with: A diagnosis of refractory glaucoma Pseudophakia (presence of posterior chamber intraocular lens) IOP ≥ 21 mmHg despite maximal tolerated medical therapy No previous glaucoma drainage device implantation in the study eye Patients with active uveitis, neovascular glaucoma, corneal decompensation, or contraindications to surgery will be excluded.
- Surgical Technique 5.1 Common Steps (Both Groups) General or local peribulbar anesthesia Fornix-based conjunctival flap in the superotemporal quadrant Priming of the AGV device Fixation of the plate 8-10 mm posterior to the limbus using 8-0 nylon sutures 5.2 Anterior Chamber Group Tube trimmed and beveled for anterior chamber entry Insertion through a scleral tunnel into the anterior chamber at the limbus, between iris and cornea Tube coverage with donor scleral patch graft and conjunctival closure 5.3 Posterior Chamber Group Complete anterior vitrectomy via pars plana approach if required to clear vitreous Tube insertion through the sclera into the ciliary sulcus, posterior to the iris and anterior to the IOL Tube secured and covered with a scleral patch graft, followed by conjunctival closure
- Follow-Up Protocol Participants will be followed at: Post-op Day 1 Week 1 Month 1, 3, 6, and 12 At each visit, the following will be assessed: IOP (Goldmann applanation) Best corrected visual acuity (Snellen/logMAR) Number of glaucoma medications Corneal endothelial cell density (specular microscopy) Central corneal thickness Slit-lamp biomicroscopy and funduscopy Recording of adverse events and complications
- Outcome Measures Primary Outcome Mean IOP at 12 months Secondary Outcomes Change in corneal endothelial cell density Proportion of eyes achieving target IOP (<21 mmHg) without medications (complete success) Proportion achieving target IOP with medications (qualified success) Number of medications required at each follow-up Rates of postoperative complications: hypotony, hyphema, choroidal detachment, corneal decompensation, tube obstruction, infection
- Data Collection and Management All data will be recorded in standardized case report forms and entered into a secure electronic database. Specular microscopy measurements will be standardized using the same device (Topcon SP-3000P) and operator for all participants. Data quality will be reviewed regularly by the study monitoring committee.
- Statistical Analysis Descriptive statistics will be used to summarize demographics and baseline characteristics. Differences between groups will be assessed using: Student's t-test for continuous variables (e.g., IOP, endothelial count) Chi-square or Fisher's exact test for categorical outcomes Kaplan-Meier survival analysis for surgical success P-values <0.05 considered statistically significant
- Safety Considerations All surgical procedures will be performed by experienced glaucoma surgeons. Standard aseptic and surgical safety protocols will be followed. Any serious adverse event (SAE) will be reported to the Institutional Review Board (IRB) and study monitoring committee.
- Significance of the Study This study will be the first randomized controlled trial in Vietnam comparing anterior vs posterior chamber Ahmed valve implantation in pseudophakic glaucoma. The results will help guide surgical decision-making in patients at risk of corneal decompensation and improve long-term visual outcomes in this challenging population.
- Conditions
- Refractory Glaucoma
- Being tested
- GDD in posterior chamber, GDD in aterior chamber
- Medical subject headings
- Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GDD in posterior chamberDevice
GDD in posterior chamber
GDD in aterior chamberDevice
GDD in anterior chamber
| Study group | Role | What they receive |
|---|---|---|
| Anterior chamber | Active comparator | Control group Receives: Device: GDD in aterior chamber |
| Study group | Experimental | AGV in Posterior chamber Receives: Device: GDD in posterior chamber |
What is being measured
The primary outcome is the main question the study is designed to answer.
IOP
Measured: IOP change at 12 months postoperatively
ECD
Measured: Corneal endothelial cell density (ECD) change from baseline to 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2025
- Study start2 Aug 2024
- Primary completion2 Aug 2027 (estimated)
- Study completion2 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Refractory GlaucomaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Eye Hospital of Ho Chi Minh City
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Quyen Vo Mai Huynh, Eye Hospital of Ho Chi Minh City
- Investigators
- Quyen Vo Mai Huynh, M.D., Principal investigator, Ho Chi Minh city Eye Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07003685
- Sponsor's protocol ID
- 320/BVM-HDDD
- Acronym
- AGV
- Status last verified
- Aug 2025
- First submitted
- 3 Jun 2025
- Last updated
- 11 Aug 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: IPD are to be shared after the study have been started.
Study at a glance
From the registry record, last updated by the sponsor on 11 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy and Safety of Posterior Chamber Glaucoma Drainage Device in Refractory Pseudophakic Glaucoma Patients
- ClinicalTrials.gov ID
- NCT07003685
- Acronym / sponsor ID
- AGV / 320/BVM-HDDD
- Conditions
- Refractory Glaucoma
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Eye Hospital of Ho Chi Minh CityUniversity, hospital or other
- Study start
- 2 Aug 2024 (actual)
- Primary completion
- 2 Aug 2027 (estimated)
- Study completion
- 2 Aug 2027 (estimated)
- First posted
- 4 Jun 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to evaluate the efficacy and safety of Ahmed glaucoma valve (AGV) implantation in the posterior chamber (ciliary sulcus) compared with the traditional anterior chamber placement in patients with refractory pseudophakic glaucoma, who are adults (>18 years), have undergone cataract surgery with intraocular lens implantation, and are unresponsive to maximal medical therapy.
The main questions it aims to answer are:
Does posterior chamber AGV implantation effectively lower intraocular pressure (IOP) compared to anterior chamber implantation? Does posterior chamber AGV implantation result in less corneal endothelial cell loss and lower rates of postoperative complications compared to anterior chamber implantation?
Researchers will compare the two groups:
Intervention group: AGV implantation in the posterior chamber (ciliary sulcus) Control group: AGV implantation in the anterior chamber
Participants will:
Undergo a baseline evaluation, including ocular examination, IOP measurement, corneal endothelial cell density (ECD) and variability, visual field testing, and optic nerve imaging.
Be randomized into two groups based on a computer-generated randomization method.
Receive either posterior chamber or anterior chamber AGV implantation. Be followed postoperatively at specified intervals (1 day, 1 week, 1 month, 3 months, 6 months, 12 months) for IOP, use of glaucoma medications, visual acuity (Snellen, logMAR), corneal ECD, and endothelial cell variability (CV).
Undergo regular assessments for postoperative complications such as hypotony, choroidal detachment, hyphema, infection, and device-related issues.
Provide informed consent after explanation of potential risks and benefits of the procedure.
This study will use a prospective, randomized controlled clinical trial design, enrolling at least 29 eyes in each group, conducted at the Glaucoma Department of Ho Chi Minh City Eye Hospital from March 2024 to March 2027
Detailed description
- Background and Rationale Refractory glaucoma in pseudophakic eyes presents a significant clinical challenge due to its resistance to maximal medical therapy and often poor response to conventional filtering surgeries. In these patients, the implantation of a glaucoma drainage device (GDD), such as the Ahmed glaucoma valve (AGV), has emerged as a viable therapeutic strategy. Traditionally, GDDs are inserted with the tube placed into the anterior chamber (AC). However, anterior chamber placement may be associated with long-term complications, such as corneal endothelial decompensation, synechiae, iris chafing, and chronic inflammation. The posterior chamber, specifically the ciliary sulcus, offers an alternative site for tube placement in pseudophakic eyes where the natural lens has already been removed. The sulcus location provides a deeper site for the tube, reducing the risk of contact with the corneal endothelium. Preliminary evidence and retrospective series suggest that sulcus placement can achieve comparable IOP-lowering efficacy while minimizing endothelial cell loss. However, to date, there is a lack of high-quality randomized controlled trials that rigorously compare the safety and efficacy outcomes of anterior vs posterior chamber tube placement in pseudophakic patients. This study is designed to address this gap in the literature by evaluating Ahmed glaucoma valve implantation with tube placement in the posterior chamber (ciliary sulcus) compared with standard anterior chamber placement in patients with refractory pseudophakic glaucoma.
- Objectives Primary Objective To evaluate and compare the intraocular pressure (IOP) reduction at 12 months following AGV implantation in the posterior chamber (ciliary sulcus) versus anterior chamber placement in eyes with refractory pseudophakic glaucoma. Secondary Objectives To assess the difference in corneal endothelial cell loss between the two groups. To compare the number of glaucoma medications required postoperatively. To evaluate the incidence of postoperative complications in both surgical groups. To determine the cumulative surgical success rates (complete and qualified success).
- Study Design This is a prospective, randomized, controlled, interventional clinical trial conducted at the Glaucoma Department of Ho Chi Minh City Eye Hospital. The study will enroll a total of 58 eyes (29 eyes per group), assigned to either anterior or posterior chamber AGV implantation via computer-generated randomization. The study period spans from March 2024 to August 2027, including a 12-month follow-up for each participant.
- Participants Eligible participants are adults aged ≥18 years with: A diagnosis of refractory glaucoma Pseudophakia (presence of posterior chamber intraocular lens) IOP ≥ 21 mmHg despite maximal tolerated medical therapy No previous glaucoma drainage device implantation in the study eye Patients with active uveitis, neovascular glaucoma, corneal decompensation, or contraindications to surgery will be excluded.
- Surgical Technique 5.1 Common Steps (Both Groups) General or local peribulbar anesthesia Fornix-based conjunctival flap in the superotemporal quadrant Priming of the AGV device Fixation of the plate 8-10 mm posterior to the limbus using 8-0 nylon sutures 5.2 Anterior Chamber Group Tube trimmed and beveled for anterior chamber entry Insertion through a scleral tunnel into the anterior chamber at the limbus, between iris and cornea Tube coverage with donor scleral patch graft and conjunctival closure 5.3 Posterior Chamber Group Complete anterior vitrectomy via pars plana approach if required to clear vitreous Tube insertion through the sclera into the ciliary sulcus, posterior to the iris and anterior to the IOL Tube secured and covered with a scleral patch graft, followed by conjunctival closure
- Follow-Up Protocol Participants will be followed at: Post-op Day 1 Week 1 Month 1, 3, 6, and 12 At each visit, the following will be assessed: IOP (Goldmann applanation) Best corrected visual acuity (Snellen/logMAR) Number of glaucoma medications Corneal endothelial cell density (specular microscopy) Central corneal thickness Slit-lamp biomicroscopy and funduscopy Recording of adverse events and complications
- Outcome Measures Primary Outcome Mean IOP at 12 months Secondary Outcomes Change in corneal endothelial cell density Proportion of eyes achieving target IOP (<21 mmHg) without medications (complete success) Proportion achieving target IOP with medications (qualified success) Number of medications required at each follow-up Rates of postoperative complications: hypotony, hyphema, choroidal detachment, corneal decompensation, tube obstruction, infection
- Data Collection and Management All data will be recorded in standardized case report forms and entered into a secure electronic database. Specular microscopy measurements will be standardized using the same device (Topcon SP-3000P) and operator for all participants. Data quality will be reviewed regularly by the study monitoring committee.
- Statistical Analysis Descriptive statistics will be used to summarize demographics and baseline characteristics. Differences between groups will be assessed using: Student's t-test for continuous variables (e.g., IOP, endothelial count) Chi-square or Fisher's exact test for categorical outcomes Kaplan-Meier survival analysis for surgical success P-values <0.05 considered statistically significant
- Safety Considerations All surgical procedures will be performed by experienced glaucoma surgeons. Standard aseptic and surgical safety protocols will be followed. Any serious adverse event (SAE) will be reported to the Institutional Review Board (IRB) and study monitoring committee.
- Significance of the Study This study will be the first randomized controlled trial in Vietnam comparing anterior vs posterior chamber Ahmed valve implantation in pseudophakic glaucoma. The results will help guide surgical decision-making in patients at risk of corneal decompensation and improve long-term visual outcomes in this challenging population.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Anterior chamber | Active comparator | Device: GDD in aterior chamberControl group |
| Study group | Experimental | Device: GDD in posterior chamberAGV in Posterior chamber |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age over 18 years.
- Diagnosis of refractory glaucoma (uncontrolled intraocular pressure despite maximal tolerated antiglaucoma medications).
- History of cataract extraction with intraocular lens implantation (pseudophakia).
- Agreement to participate in the study and ability to comply with outpatient follow-up requirements
Key exclusion criteria (4 listed)
- Presence of corneal opacities that preclude accurate endothelial assessment.
- Co-existing corneal diseases that could affect endothelial cell status (e.g., Fuchs' dystrophy, corneal edema).
- Single-eye (monocular) status.
- Systemic medical conditions affecting coagulation or carrying increased surgical risk (e.g., uncontrolled diabetes, bleeding disorders)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GDD in posterior chamberGDD in posterior chamber | Device | Study group |
| GDD in aterior chamberGDD in anterior chamber | Device | Anterior chamber |
Primary outcome
IOP
Time frame: IOP change at 12 months postoperatively
ECD
Time frame: Corneal endothelial cell density (ECD) change from baseline to 12 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Aug 2025.
- Individual participant dataSharing planned: Yes. IPD are to be shared after the study have been started.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Quyen Vo Mai Huynh, M.D. principal investigator
Ho Chi Minh city Eye Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing GDD in posterior chamber and GDD in aterior chamber in people with Refractory Glaucoma, run by Eye Hospital of Ho Chi Minh City at 1 site in Vietnam.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 11 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Vietnam. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
IOP (time frame: IOP change at 12 months postoperatively). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Aug 2025.