GlaucomaPhase 3NCT01004900
Intraocular Pressure (IOP) Lowering Effect of Selective Laser Trabeculoplasty Versus Prostaglandin Analogues in Angle Closure Glaucoma
A Phase 3 study testing Selective Laser Trabeculoplasty and Travoprost/ Timolol/ Azopt/ Brimonidine in people with Glaucoma, run by Singapore Eye Research Institute at 1 site in Singapore.
Trial summary
Glaucoma affects 66 million people worldwide and is the leading cause of irreversible blindness, and Primary angle-closure glaucoma (PACG) is a major form of glaucoma in Asia. Laser peripheral iridotomy (LPI) has been advocated as the first line treatment in all cases of PACG. Read more about this study
- Who is it for?
- Ages 21 years and older
- Conditions the study is for
- Glaucoma
- What is being tested?
- Selective Laser Trabeculoplasty and Travoprost/ Timolol/ Azopt/ Brimonidine
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteSingapore
- Study dates
- Jun 2009to Mar 2011
- Phase
- Phase 3
- 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 21 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of primary angle closure or primary angle closure glaucoma with documented pre-LPI angle closure of ≥180 degrees of the angle (Trabecular meshwork not visible in primary position using gonioscopy)
- One month post LPI, angle has opened up (visibility of trabecular meshwork) for at least 180 degrees of the angle
- Intraocular pressure between 21-≤30 mmHg without treatment following LPI OR Intraocular pressure between 21-≤30 mmHg after wash out regimen as described below for patients who are already medications following LPI.
- Informed Consent
- Age more than 21 years
Who cannot join
- Secondary causes of angle closure like subluxed lens, uveitis, trauma and neovascular glaucoma
- Presence of advanced sight-threatening glaucoma defined as vertical cup-disc ratio > 0.9 or visual field constriction involving <100 of the central visual field performed with the Humphrey Visual Field Analyzer II using the SITA STD algorithm with a 24-2 test pattern.
- Cataract that is deemed significant enough to require surgery during the course of the trial or that makes field testing or optic disc imaging not technically possible- visual acuity less than 20/40 due to any type of cataract.
- Previous intraocular surgery, SLT, ALT, refractive surgery or iridoplasty.
- Documented previous history of angle closure.
- Use of contact lens
Show all 9Show fewer
- Chronic use of topical or systemic steroids
- Participation in another therapeutic drug study within the last 30 days
- Severe health problems precluding follow-up such as end-stage heart disease, kidney disease, respiratory disease, or cancer and life expectancy less than one year.
Trial locations and contacts
1 site in 1 country.
Singapore1 site, 1 recruiting
- Recruiting
Singapore National Eye Centre
Singapore, 168751
Tin Aung, FRCOphth, 62277255, aung.tin@snec.com.sg
Tin Aung, FRCOphth
About this study
Official title: Comparison of Selective Laser Trabeculoplasty With Prostaglandin Analogues for Lowering Intraocular Pressure in Eyes With Primary Angle Closure Glaucoma
Glaucoma affects 66 million people worldwide and is the leading cause of irreversible blindness, and Primary angle-closure glaucoma (PACG) is a major form of glaucoma in Asia.
Laser peripheral iridotomy (LPI) has been advocated as the first line treatment in all cases of PACG. In addition to relieving the relative pupil block element of the condition, it can open up the drainage angle, alleviating appositional and synechial angle-closure and in the long-term this may control intraocular pressure (IOP) and prevent progression of glaucomatous optic neuropathy. However recent data indicate that iridotomy is not successful in controlling IOP in the long term, and the majority of cases develop a clinically significant rise in IOP requiring medical therapy or surgery.
Read more
Laser trabeculoplasty has been a recognized treatment option for Primary open angle glaucoma (POAG) since the 1980s. Recently a more selective and less destructive method of performing laser trabeculoplasty has evolved. Selective Laser Trabeculoplasty (SLT) specifically targets the pigmented trabecular meshwork cells without producing collateral damage and destruction to adjacent structures. Morphologic study performed on human autopsy eyes treated with SLT noted no structural or collateral thermal damage to the trabecular beams in the uveal and corneoscleral meshwork. As SLT specifically has its effect on the targeted pigmented trabecular meshwork it is unlikely to generate PAS. It may be a useful treatment option for PACG patients in whom the angle has widened following laser peripheral iridotomy.
The proposed study is a randomized controlled trial to assess the effectiveness of SLT in reducing IOP in cases of PACG in which the angle has opened up following LPI, but IOP remains high(>21 mmHg). 100 subjects will be randomized to receive either SLT or medical treatment to achieve IOP control. They will be followed up for 6 months.
Read the detailed description
STUDY OBJECTIVES AND PURPOSE
The aim of this study is to determine whether selective laser trabeculoplasty (SLT) is an effective treatment for lowering intraocular pressure (IOP) in patients with primary angle closure glaucoma (PACG), compared to prostaglandin analogues, the current first choice IOP-lowering medical therapy.
STUDY DESIGN The study design for this project is a prospective randomized controlled trial. It will not be possible to blind either the subject or observer to the intervention due to the use of laser in the intervention group and medical therapy in the control group. Subjects will then be followed-up for 6 months
STUDY POPULATION
The study population will be patients with primary angle closure glaucoma attending the Singapore National Eye Centre, who fulfil the inclusion criteria and are willing to take part in the study.
WASH OUT REGIMEN: for patients already on medication
Eligible patients who are already on one or two-glaucoma medications are required to complete a washout period before being randomized. Washout periods will vary according to the previous medication used and are as follows:
Prostaglandin analogues 4 weeks Beta blockers 3 weeks Adrenergic agonist 2 weeks Cholinergic agonist 5 days Carbonic Anhydrase Inhibitors 5 days
Pre-study washout period check Patients who are on prostaglandin analogues or beta blockers prior to the study will be required to undergo a washout period of 3 and 4 weeks respectively prior to the study. For this group of patients, there will be a safety check during the second week. Patients whose IOP>30 mm hg during this washout check will be stopped from further washout and be withdrawn from the study.
Treatment of subjects
PLANNED INTERVENTION
Selective laser trabeculoplasty procedure The laser procedure will be performed on all patients as follows
- A drop of Brimonidine will be instilled into the eye to be treated 15 minutes prior to the procedure.
- Topical anaesthesia will be administered and the Latina SLT lens and coupling fluid will be used for the procedure.
- The slit-lamp attached to the laser will be focused on the full height of the trabecular meshwork.
- The laser power will be set to 0.6mJ and increased in 0.1mJ steps until small champagne -like bubbles appear from the treated area of the trabecular meshwork. The laser spot size would be 400µm.
- Approximately 60-120 non-overlapping shots will be placed onto at least 180 degrees of the trabecular meshwork that is visible and without PAS. More non-overlapping shots can be placed if sufficient extent of the trabeculum is visible.
Post - laser the patient will be given a one week course of topical Prednisolone forte four times a day for the treated eye.
Intraocular pressure will be checked 30-60 minutes after the procedure. IOP spikes of ≥ 5mmHg or to a level of ≥ 28mmHg will be treated with Diamox if not contraindicated.
Intraocular pressure will be checked one week post SLT. If the IOP ≥28mmHg, tablet diamox will be given for 3 days.
Retreatment of SLT If IOP remains elevated, one further treatment of SLT will be given to the patient. This treatment will be administered either at the four week or three month follow up visit.
If there is a <20% reduction of IOP from baseline either at the week 4 or month 3 follow-up visit, then SLT will be repeated using the same laser parameters as described above. The patient will be seen again one week after the repeated laser treatment.
IIf the IOP is <21mmHg or there is >20% reduction of IOP from baseline at at the week 4 or month 3 follow-up visit, then no further treatment will be given to the patient.
IOP will be checked one week after repeat SLT. If the IOP is still high (>24 mmHg), treatment modification will be provided (see Treatment Modification below).
Control group Those patients randomized to the control group will be commenced on topical treatment to lower the IOP. The agent for lowering IOP will be a prostaglandin analogue, Travoprost, which will be applied once a day at night.
A stepwise addition of Timolol 0.5%, dorzolamide or brimonidine will be implemented until IOP is controlled (see below Treatment Modification).
- Conditions
- Glaucoma
- Being tested
- Selective Laser Trabeculoplasty, Travoprost/ Timolol/ Azopt/ Brimonidine
- Keywords
- Glaucoma, Angle Closure, Selective laser trabeculoplasty, Primary Angle Closure Disease
- Medical subject headings
- Glaucoma, Glaucoma, Angle-Closure
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Selective Laser TrabeculoplastyProcedure or surgery
This is a laser procedure used to treat glaucoma by reducing the pressure in the eye. SLT works by using laser light to stimulate the body's own healing response to lower your eye pressure. Using a special wavelength and energy, the laser affects only pigmented (melanin containing) cells of your eye. SLT improves the flow of fluid in the eye, which in turn lowers your eye pressure.
Travoprost/ Timolol/ Azopt/ BrimonidineDrug
Travoprost (Topical eye drops) administered once daily before sleep
| Study group | Role | What they receive |
|---|---|---|
| Trabeculoplasty | Active comparator | Not described Receives: Procedure: Selective Laser Trabeculoplasty |
| Control (Medication) | Active comparator | Not described Receives: Drug: Travoprost/ Timolol/ Azopt/ Brimonidine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Intraocular Pressure
Fluid pressure inside the eye
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Oct 2009 (estimated)
- Study startJun 2009
- Primary completionMar 2011 (estimated)
- Study completionMar 2011 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 90 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Singapore Eye Research Institute
- Sponsor type
- University, hospital or other
- Investigators
- Tin Aung, FRCOphth, Principal investigator, Singapore National Eye Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01004900
- Sponsor's protocol ID
- R657/07/2009
- Status last verified
- May 2010
- First submitted
- 29 Oct 2009
- Last updated
- 12 May 2010
- Results posted
- No
- Data monitoring committee
- No
Publications
Narayanaswamy A, Leung CK, Istiantoro DV, Perera SA, Ho CL, Nongpiur ME, Baskaran M, Htoon HM, Wong TT, Goh D, Su DH, Belkin M, Aung T. Efficacy of selective laser trabeculoplasty in primary angle-closure glaucoma: a randomized clinical trial. JAMA Ophthalmol. 2015 Feb;133(2):206-12. doi: 10.1001/jamaophthalmol.2014.4893.
PubMed 25429421
Study at a glance
From the registry record, last updated by the sponsor on 12 May 2010. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Selective Laser Trabeculoplasty With Prostaglandin Analogues for Lowering Intraocular Pressure in Eyes With Primary Angle Closure Glaucoma
- ClinicalTrials.gov ID
- NCT01004900
- Acronym / sponsor ID
- R657/07/2009
- Conditions
- Glaucoma
- Keywords
- Glaucoma, Angle Closure, Selective laser trabeculoplasty, Primary Angle Closure Disease
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 90 participants (estimated)
- Lead sponsor
- Singapore Eye Research InstituteUniversity, hospital or other
- Study start
- Jun 2009
- Primary completion
- Mar 2011 (estimated)
- Study completion
- Mar 2011 (estimated)
- First posted
- 30 Oct 2009 (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.
Glaucoma affects 66 million people worldwide and is the leading cause of irreversible blindness, and Primary angle-closure glaucoma (PACG) is a major form of glaucoma in Asia.
Laser peripheral iridotomy (LPI) has been advocated as the first line treatment in all cases of PACG. In addition to relieving the relative pupil block element of the condition, it can open up the drainage angle, alleviating appositional and synechial angle-closure and in the long-term this may control intraocular pressure (IOP) and prevent progression of glaucomatous optic neuropathy. However recent data indicate that iridotomy is not successful in controlling IOP in the long term, and the majority of cases develop a clinically significant rise in IOP requiring medical therapy or surgery.
Laser trabeculoplasty has been a recognized treatment option for Primary open angle glaucoma (POAG) since the 1980s. Recently a more selective and less destructive method of performing laser trabeculoplasty has evolved. Selective Laser Trabeculoplasty (SLT) specifically targets the pigmented trabecular meshwork cells without producing collateral damage and destruction to adjacent structures. Morphologic study performed on human autopsy eyes treated with SLT noted no structural or collateral thermal damage to the trabecular beams in the uveal and corneoscleral meshwork. As SLT specifically has its effect on the targeted pigmented trabecular meshwork it is unlikely to generate PAS. It may be a useful treatment option for PACG patients in whom the angle has widened following laser peripheral iridotomy.
The proposed study is a randomized controlled trial to assess the effectiveness of SLT in reducing IOP in cases of PACG in which the angle has opened up following LPI, but IOP remains high(>21 mmHg). 100 subjects will be randomized to receive either SLT or medical treatment to achieve IOP control. They will be followed up for 6 months.
Detailed description
STUDY OBJECTIVES AND PURPOSE
The aim of this study is to determine whether selective laser trabeculoplasty (SLT) is an effective treatment for lowering intraocular pressure (IOP) in patients with primary angle closure glaucoma (PACG), compared to prostaglandin analogues, the current first choice IOP-lowering medical therapy.
STUDY DESIGN The study design for this project is a prospective randomized controlled trial. It will not be possible to blind either the subject or observer to the intervention due to the use of laser in the intervention group and medical therapy in the control group. Subjects will then be followed-up for 6 months
STUDY POPULATION
The study population will be patients with primary angle closure glaucoma attending the Singapore National Eye Centre, who fulfil the inclusion criteria and are willing to take part in the study.
WASH OUT REGIMEN: for patients already on medication
Eligible patients who are already on one or two-glaucoma medications are required to complete a washout period before being randomized. Washout periods will vary according to the previous medication used and are as follows:
Prostaglandin analogues 4 weeks Beta blockers 3 weeks Adrenergic agonist 2 weeks Cholinergic agonist 5 days Carbonic Anhydrase Inhibitors 5 days
Pre-study washout period check Patients who are on prostaglandin analogues or beta blockers prior to the study will be required to undergo a washout period of 3 and 4 weeks respectively prior to the study. For this group of patients, there will be a safety check during the second week. Patients whose IOP>30 mm hg during this washout check will be stopped from further washout and be withdrawn from the study.
Treatment of subjects
PLANNED INTERVENTION
Selective laser trabeculoplasty procedure The laser procedure will be performed on all patients as follows
- A drop of Brimonidine will be instilled into the eye to be treated 15 minutes prior to the procedure.
- Topical anaesthesia will be administered and the Latina SLT lens and coupling fluid will be used for the procedure.
- The slit-lamp attached to the laser will be focused on the full height of the trabecular meshwork.
- The laser power will be set to 0.6mJ and increased in 0.1mJ steps until small champagne -like bubbles appear from the treated area of the trabecular meshwork. The laser spot size would be 400µm.
- Approximately 60-120 non-overlapping shots will be placed onto at least 180 degrees of the trabecular meshwork that is visible and without PAS. More non-overlapping shots can be placed if sufficient extent of the trabeculum is visible.
Post - laser the patient will be given a one week course of topical Prednisolone forte four times a day for the treated eye.
Intraocular pressure will be checked 30-60 minutes after the procedure. IOP spikes of ≥ 5mmHg or to a level of ≥ 28mmHg will be treated with Diamox if not contraindicated.
Intraocular pressure will be checked one week post SLT. If the IOP ≥28mmHg, tablet diamox will be given for 3 days.
Retreatment of SLT If IOP remains elevated, one further treatment of SLT will be given to the patient. This treatment will be administered either at the four week or three month follow up visit.
If there is a <20% reduction of IOP from baseline either at the week 4 or month 3 follow-up visit, then SLT will be repeated using the same laser parameters as described above. The patient will be seen again one week after the repeated laser treatment.
IIf the IOP is <21mmHg or there is >20% reduction of IOP from baseline at at the week 4 or month 3 follow-up visit, then no further treatment will be given to the patient.
IOP will be checked one week after repeat SLT. If the IOP is still high (>24 mmHg), treatment modification will be provided (see Treatment Modification below).
Control group Those patients randomized to the control group will be commenced on topical treatment to lower the IOP. The agent for lowering IOP will be a prostaglandin analogue, Travoprost, which will be applied once a day at night.
A stepwise addition of Timolol 0.5%, dorzolamide or brimonidine will be implemented until IOP is controlled (see below Treatment Modification).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Trabeculoplasty | Active comparator | Procedure: Selective Laser Trabeculoplasty |
| Control (Medication) | Active comparator | Drug: Travoprost/ Timolol/ Azopt/ Brimonidine |
Who may qualify
- Ages
- 21 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Diagnosis of primary angle closure or primary angle closure glaucoma with documented pre-LPI angle closure of ≥180 degrees of the angle (Trabecular meshwork not visible in primary position using gonioscopy)
- One month post LPI, angle has opened up (visibility of trabecular meshwork) for at least 180 degrees of the angle
- Intraocular pressure between 21-≤30 mmHg without treatment following LPI OR Intraocular pressure between 21-≤30 mmHg after wash out regimen as described below for patients who are already medications following LPI.
- Informed Consent
- Age more than 21 years
Key exclusion criteria (9 listed)
- Secondary causes of angle closure like subluxed lens, uveitis, trauma and neovascular glaucoma
- Presence of advanced sight-threatening glaucoma defined as vertical cup-disc ratio > 0.9 or visual field constriction involving <100 of the central visual field performed with the Humphrey Visual Field Analyzer II using the SITA STD algorithm with a 24-2 test pattern.
- Cataract that is deemed significant enough to require surgery during the course of the trial or that makes field testing or optic disc imaging not technically possible- visual acuity less than 20/40 due to any type of cataract.
- Previous intraocular surgery, SLT, ALT, refractive surgery or iridoplasty.
- Documented previous history of angle closure.
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 |
|---|---|---|
| Selective Laser TrabeculoplastyThis is a laser procedure used to treat glaucoma by reducing the pressure in the eye. SLT works by using laser light to stimulate the body's own healing response to lower your eye pressure. Using a special wavelength and energy, the laser affects only pigmented (melanin containing) cells of your eye. SLT improves the flow of fluid in the eye, which in turn lowers your eye pressure. | Procedure or surgery | Trabeculoplasty |
| Travoprost/ Timolol/ Azopt/ BrimonidineTravoprost (Topical eye drops) administered once daily before sleep | Drug | Control (Medication) |
Primary outcome
Intraocular Pressure
Time frame: 6 months
Fluid pressure inside the eye
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 May 2010.
- Derived from this study: PubMed 25429421Narayanaswamy A, Leung CK, Istiantoro DV, Perera SA, Ho CL, Nongpiur ME, Baskaran M, Htoon HM, Wong TT, Goh D, Su DH, Belkin M, Aung T. Efficacy of selective laser trabeculoplasty in primary angle-closure glaucoma: a randomized clinical trial. JAMA Ophthalmol. 2015 Feb;133(2):206-12. doi: 10.1001/jamaophthalmol.2014.4893.
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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.
Tin Aung, FRCOphth principal investigator
Singapore National Eye Centre
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Selective Laser Trabeculoplasty and Travoprost/ Timolol/ Azopt/ Brimonidine in people with Glaucoma, run by Singapore Eye Research Institute at 1 site in Singapore.
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 5 inclusion and 9 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 12 May 2010. 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 Singapore. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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 Tin Aung, FRCOphth (62277255, aung.tin@snec.com.sg), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Intraocular Pressure (time frame: 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01004900, which also lists 1 linked publication.
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 12 May 2010.