GlaucomaPhase 4NCT01535768
Effect of Prophylactic Aqueous Suppression on Hyperencapsulation of Ahmed Glaucoma Valves
A Phase 4 study testing Aqueous Suppressant Eye Drops in people with Glaucoma, run by Credit Valley EyeCare at 1 site in Canada.
Trial summary
After implantation of an Ahmed glaucoma valve in patients with glaucoma, hyperencapsulation phase is an unwanted postoperative phenomenon, typically occurring with the free 3 months postoperatively. When this does occur, it is treated with aqueous suppressant eye drops. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Glaucoma
- What is being tested?
- Aqueous Suppressant Eye Drops
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 150 participants
- Where
- 1 siteCanada
- Study dates
- Feb 2012to Jun 2020
- Phase
- Phase 4
- Are there results?
- None posted in the registry
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
- clinical diagnosis of glaucoma
- scheduled for Ahmed glaucoma valve surgery, with or without simultaneous cataract surgery
Who cannot join
- neovascular glaucoma
- uveitic glaucoma
- prior tube shunt surgery
- prior cyclodestruction procedure
- abnormal cornea that would make IOP measurements unreliable
- sulfa allergy
Show all 10Show fewer
- systemic contraindication to acetazolamide use
- inability to attend follow up visits
- intraocular pressure greater than 21 at postoperative week 1 (represents primary failure of the valve)
- anterior chamber fill within the first week postoperatively
Trial locations and contacts
1 site in 1 country.
Canada1 site, 1 recruiting
- Recruiting
Credit Valley Eye Care
Mississauga, Ontario, L5L1W8
Amandeep S Rai, MD, 647-987-4724, amandeeprai85@gmail.com
Devesh K Varma, MD FRCSC
About this study
After implantation of an Ahmed glaucoma valve in patients with glaucoma, hyperencapsulation phase is an unwanted postoperative phenomenon, typically occurring with the free 3 months postoperatively. When this does occur, it is treated with aqueous suppressant eye drops.
This study aims to determine if it is possible to reduce the rate of hyperencapsulation phase. Patients in the treatment group will receive aqueous suppressant eye drops before the hyperencapsulation phase starts. Treatment will be initiated once their intraocular pressure is above a pre-defined level, and will target a pre-defined range.
Read the detailed description
Patients with glaucoma requiring tube shunt surgery, with or without simultaneous cataract surgery, will be enrolled in this prospective randomized controlled study at ten sites across Canada and the United States (to be determined). Patients with highly advanced glaucoma at high risk of fixation loss, neovascular glaucoma, chronic uveitis, marked corneal disease, sulfa allergy, renal disease or any contraindication to diamox use will be excluded.
Patients scheduled for Ahmed glaucoma valve surgery, with or without cataract surgery, will be randomized using a stratified central block randomization approach to the treatment group or control group. Those scheduled for combined cataract and tube shunt will be randomized separately from those receiving tube shunt alone. Surgeons will be masked to the postoperative treatment or control group at the time of surgery since randomization will occur when the patient is one-week postoperative Those in the treatment group would receive short-term prophylactic aqueous suppression for the first 3 postoperative months to maintain intraocular pressure (IOP) between 7 and 10mmHg. The control group would not receive prophylactic aqueous suppression, but would be treated using a similar protocol as the treatment group in the event that an Hyperencapsulation phase (HEP) endpoint is met.
Prophylactic aqueous suppression in the study group would only be given for the 1st 3 months postoperatively. At the 3 month visit, aqueous suppression will be stopped. The primary outcome measure is washout IOP at 4 months postoperative. Washout IOP will be checked one month after discontinuation (earlier if needed i.e., advanced glaucoma patients).
Beyond 3 months, aqueous suppressants would be used at the clinician's discretion based on IOP.
At the conclusion of the study, the 4-month postoperative washout IOP, the incidence of HEP, the 12-month IOP, the 13-month washout IOP, and medication requirement would be compared between the treatment and control arms.
- Conditions
- Glaucoma
- Being tested
- Aqueous Suppressant Eye Drops
- Medical subject headings
- Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Aqueous Suppressant Eye DropsDrug
Also called Timoptic, Trusopt, Azopt, Alphagan-P
Aqueous suppressant eye drops added stepwise to achieve IOP between 7-10mmHg. First, a beta blocker eye drop (timolol 0.25% 1 gtts in study eye BID OR timolol 0.5% 1 gtts in study eye BID).
Next, a topical carbonic anhydrase inhibitor eye drop. (brinzolamide 1% 1 gtts in study eye TID OR dorzolamide 2% 1 gtts in study eye TID) Next, a topical alpha agonist eye drop. (brimonidine 0.1% 1 gtts in study eye TID OR brimonidine 0.15% 1 gtts in study eye TID).
Next, a topical prostaglandin analogue eye drop. (latanoprost 0.005% 1 gtts in study eye qhs OR travoprost 0.004% 1 gtts in study eye qhs OR bimatoprost 0.01% 1 gtts in study eye qhs OR bimatoprost 0.03% 1 gtts in study eye qhs) Finally, stop the topical carbonic anhydrase inhibitor eye drop and start oral acetazolamide. (acetazolamide 250mg PO OD)
| Study group | Role | What they receive |
|---|---|---|
| Intervention Group | Experimental | Patients randomized to the intervention group will receive aqueous suppressant eyedrops in a stepwise fashion in order to maintain their intraocular pressure between 7-10mmHg. Receives: Drug: Aqueous Suppressant Eye Drops |
| Control Group | No intervention | Patients randomized to the control group will receive standard of care treatment. They will not be aqueous suppressed within the first three postoperative months unless the bleb hyperencapsulates. (If they experience the hyperencapsulation phase, they will continue to receive standard of care treatment, which would then be aqueous suppressant eye drops added in a stepwise fashion) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Intraocular pressure
The primary outcome measure is intraocular pressure (IOP) at 4 months postoperative. This will be a washout IOP (i.e. all glaucoma eye drops will be stopped at 3 months postoperative in all study patients)
Measured: 4 months postoperative
Secondary outcomes (4)
Hyperencapsulation phase (HEP)
The HEP endpoint will be met within the first 3 postoperative months if all of the following are met:
- IOP increase by 5mmHg or greater compared to previous visit
- A bleb appearance in keeping with encapsulation (raised, thickened, firm, dome-shaped)
- no other reason for IOP increase
Measured: first 3 months postoperative
Qualified Ahmed Glaucoma Valve success
An eye will have qualified success of the Ahmed glaucoma valve if the intraocular pressure (IOP) is at or below 18mmHg at 12 months with use of medications.
Measured: 12 months
Absolute Ahmed Glaucoma Valve success
An eye will have absolute success of the Ahmed glaucoma valve if the intraocular pressure (IOP) is at or below 18mmHg at 13 months without use of medications. Medications will be stopped at the 12 month visit, and so eyes will be washed out at 13 months.
Measured: 13 months
Number of glaucoma medications
Will count the number of glaucoma medication classes required to achieve qualified Ahmed Glaucoma Valve success at 12 months.
Measured: 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Feb 2012 (estimated)
- Study startFeb 2012
- Primary completionJun 2018 (estimated)
- Study completionJun 2020 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for 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 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Credit Valley EyeCare
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Canadian Glaucoma Clinical Research Council
- Responsible party
- Principal investigator, Amandeep Rai, Credit Valley EyeCare
- Investigators
- Devesh K Varma, MD FRCSC, Principal investigator, University of TorontoIke K Ahmed, MD FRCSC, Principal investigator, University of TorontoAmandeep S Rai, MD, Study director, University of Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01535768
- Sponsor's protocol ID
- PASAGV2012
- Status last verified
- Jul 2017
- First submitted
- 13 Feb 2012
- Last updated
- 21 Jul 2017
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 21 Jul 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Prophylactic Aqueous Suppression on Hyperencapsulation of Ahmed Glaucoma Valves
- ClinicalTrials.gov ID
- NCT01535768
- Acronym / sponsor ID
- PASAGV2012
- Conditions
- Glaucoma
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Credit Valley EyeCareIndustry (pharma, biotech, devices)
- Collaborators
- Canadian Glaucoma Clinical Research Council
- Study start
- Feb 2012
- Primary completion
- Jun 2018 (estimated)
- Study completion
- Jun 2020 (estimated)
- First posted
- 20 Feb 2012 (estimated)
- 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.
After implantation of an Ahmed glaucoma valve in patients with glaucoma, hyperencapsulation phase is an unwanted postoperative phenomenon, typically occurring with the free 3 months postoperatively. When this does occur, it is treated with aqueous suppressant eye drops.
This study aims to determine if it is possible to reduce the rate of hyperencapsulation phase. Patients in the treatment group will receive aqueous suppressant eye drops before the hyperencapsulation phase starts. Treatment will be initiated once their intraocular pressure is above a pre-defined level, and will target a pre-defined range.
Detailed description
Patients with glaucoma requiring tube shunt surgery, with or without simultaneous cataract surgery, will be enrolled in this prospective randomized controlled study at ten sites across Canada and the United States (to be determined). Patients with highly advanced glaucoma at high risk of fixation loss, neovascular glaucoma, chronic uveitis, marked corneal disease, sulfa allergy, renal disease or any contraindication to diamox use will be excluded.
Patients scheduled for Ahmed glaucoma valve surgery, with or without cataract surgery, will be randomized using a stratified central block randomization approach to the treatment group or control group. Those scheduled for combined cataract and tube shunt will be randomized separately from those receiving tube shunt alone. Surgeons will be masked to the postoperative treatment or control group at the time of surgery since randomization will occur when the patient is one-week postoperative Those in the treatment group would receive short-term prophylactic aqueous suppression for the first 3 postoperative months to maintain intraocular pressure (IOP) between 7 and 10mmHg. The control group would not receive prophylactic aqueous suppression, but would be treated using a similar protocol as the treatment group in the event that an Hyperencapsulation phase (HEP) endpoint is met.
Prophylactic aqueous suppression in the study group would only be given for the 1st 3 months postoperatively. At the 3 month visit, aqueous suppression will be stopped. The primary outcome measure is washout IOP at 4 months postoperative. Washout IOP will be checked one month after discontinuation (earlier if needed i.e., advanced glaucoma patients).
Beyond 3 months, aqueous suppressants would be used at the clinician's discretion based on IOP.
At the conclusion of the study, the 4-month postoperative washout IOP, the incidence of HEP, the 12-month IOP, the 13-month washout IOP, and medication requirement would be compared between the treatment and control arms.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intervention Group | Experimental | Drug: Aqueous Suppressant Eye DropsPatients randomized to the intervention group will receive aqueous suppressant eyedrops in a stepwise fashion in order to maintain their intraocular pressure between 7-10mmHg. |
| Control Group | No intervention | –Patients randomized to the control group will receive standard of care treatment. They will not be aqueous suppressed within the first three postoperative months unless the bleb hyperencapsulates. (If they experience the hyperencapsulation phase, they will continue to receive standard of care treatment, which would then be aqueous suppressant eye drops added in a stepwise fashion) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- clinical diagnosis of glaucoma
- scheduled for Ahmed glaucoma valve surgery, with or without simultaneous cataract surgery
Key exclusion criteria (10 listed)
- neovascular glaucoma
- uveitic glaucoma
- prior tube shunt surgery
- prior cyclodestruction procedure
- abnormal cornea that would make IOP measurements unreliable
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 |
|---|---|---|
| Aqueous Suppressant Eye DropsAlso: Timoptic, Trusopt, Azopt, Alphagan-PAqueous suppressant eye drops added stepwise to achieve IOP between 7-10mmHg. First, a beta blocker eye drop (timolol 0.25% 1 gtts in study eye BID OR timolol 0.5% 1 gtts in study eye BID). Next, a topical carbonic anhydrase inhibitor eye drop. (brinzolamide 1% 1 gtts in study eye TID OR dorzolamide 2% 1 gtts in study eye TID) Next, a topical alpha agonist eye drop. (brimonidine 0.1% 1 gtts in study eye TID OR brimonidine 0.15% 1 gtts in study eye TID). Next, a topical prostaglandin analogue eye drop. (latanoprost 0.005% 1 gtts in study eye qhs OR travoprost 0.004% 1 gtts in study eye qhs OR bimatoprost 0.01% 1 gtts in study eye qhs OR bimatoprost 0.03% 1 gtts in study eye qhs) Finally, stop the topical carbonic anhydrase inhibitor eye drop and start oral acetazolamide. (acetazolamide 250mg PO OD) | Drug | Intervention Group |
Primary outcome
Intraocular pressure
Time frame: 4 months postoperative
The primary outcome measure is intraocular pressure (IOP) at 4 months postoperative. This will be a washout IOP (i.e. all glaucoma eye drops will be stopped at 3 months postoperative in all study patients)
4 secondary outcomes
Hyperencapsulation phase (HEP)
Time frame: first 3 months postoperative
Qualified Ahmed Glaucoma Valve success
Time frame: 12 months
Absolute Ahmed Glaucoma Valve success
Time frame: 13 months
Number of glaucoma medications
Time frame: 12 months
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Jul 2017.
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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. This study is not recruiting at the moment.
Devesh K Varma, MD FRCSC principal investigator
University of Toronto
Ike K Ahmed, MD FRCSC principal investigator
University of Toronto
Amandeep S Rai, MD study director
University of Toronto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Aqueous Suppressant Eye Drops in people with Glaucoma, run by Credit Valley EyeCare at 1 site in Canada.
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 2 inclusion and 10 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: status not confirmed, as of the sponsor's last update on 21 Jul 2017. 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 Canada. 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Amandeep S Rai, MD (647-987-4724, amandeeprai85@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Intraocular pressure (time frame: 4 months postoperative). 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 21 Jul 2017.