Primary Angle Glaucoma Closure SuspectNCT04741919
Superior vs Temporal Laser Peripheral Iridotomy in Primary Angle Closure Suspects (PACS)
A study testing Yag Laser peripheral Iridotomy in people with Primary Angle Glaucoma Closure Suspect, run by Sunnybrook Health Sciences Centre at 1 site in Canada.
Trial summary
Basic Study Design: Prospective, randomized, single-center, single-blinded study to compare dysphotopsias and pain recollection immediately 2 weeks, and 3 months after LPI in PACS patients who have a clear indication for bilateral LPI. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Primary Angle Glaucoma Closure Suspect
- What is being tested?
- Yag Laser peripheral Iridotomy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 200 participants
- Where
- 1 siteCanada
- Study dates
- 25 Nov 2020to 31 Dec 2024
- Phase
- Interventional
- 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
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- clinical evidence of bilateral occludable angles (PACS) defined as:
- Peripheral anterior synechia (PAS) absent and trabecular meshwork not visible in ≥6 clock hours under non-indentation gonioscopy, Along with,
- absence of PAC or PACG, in both eyes.
- macular and optic nerve OCT within the 95% range of the normative database for patients to be included in this study.
Who cannot join
- evidence of unilateral PACS,
- a history suggestive of an acute angle closure attack (based on symptoms) documented intraocular pressure over 30 mmHg,
- or any sign of Angle Closure Glaucoma (manifest glaucomatous neuropathy detected by OCT).
- Patients with previous ocular surgeries will also be excluded.
Trial locations and contacts
1 site in 1 country.
Canada1 site, 1 recruiting
- Recruiting
Sunnybrook Health Sciences Centre
Toronto, Ontario, M4N 3M5
Catherine Birt, MD, FRCSC, 416-480-5882, catherine.birt@sunnybrook.ca
About this study
Official title: Randomized Prospective Study of Superior Versus Temporal Laser Peripheral Iridotomy (LPI) in Primary Angle Closure Suspects (PACS)
Basic Study Design: Prospective, randomized, single-center, single-blinded study to compare dysphotopsias and pain recollection immediately 2 weeks, and 3 months after LPI in PACS patients who have a clear indication for bilateral LPI. Our null hypothesis is that there is no difference in dysphotopsia or pain levels by LPI position. Our alternate hypothesis is that there are more dysphotopsias superiorly and more pain temporally.
Read the detailed description
The study objective is to describe the difference in the incidence of dysphotopsias and sensation of pain both immediately, 2 weeks and 3 months after superior or temporal LPI. The main primary outcome variable will be the presence of dysphotopsias and the recollection of pain graded by a standardized pain scale.
Stratified Block Randomization: 200 patients will be recruited from participating centre. For each patient, the order of the eye to be treated as well as the position of the LPI superior or temporal will be randomized.
Methods:
Subjects: Patients included in the study will be patients referred for a glaucoma evaluation or in follow up at Sunnybrook Science Center who are diagnosed as PACS and have therefore an indication for bilateral LPIs.
Interventions: All patients eligible will be examined by the principal investigator, including a slit lamp assessment of the anterior segment, gonioscopy of the angle and stereoscopic optic nerve examination with a 78 Diopters lens. Intraocular pressure (IOP) will be measured with applanation tonometry. Patients will be assessed with a macular and optic nerve OCT to rule out glaucoma.
Only bilateral PACS patients will be included. One randomly selected eye will receive superior LPI while contralateral eye temporal LPI. At the 2 week and 3 month follow up visits patients will be asked about dysphotopsias in one or both eyes and their recollection of pain will be graded. Other distractors will be included in the questionnaire such as increased tearing sensation.
Laser peripheral iridotomy will be performed using neo-dynium:yttrium:aluminium-garnet laser after pretreatment with 2% pilocarpine and brimonidine 0.15%. Superior LPIs will be placed between the 11- and 1-o'clock positions such that they were covered completely by the upper eyelid; nasal/temporal LPIs will be placed between the 2- and 4-o'clock positions or the 8- and 10-o'clock positions such that they were completely clear of the lid margin. Preference will be given to iris crypts, avoiding iris vessels when possible. Laser peripheral iridotomies will be performed in both eyes during the same visit and will be confirmed to be patent after the procedure. Intraoperative data collected will include initial per-shot laser energy in milli joules, number of laser shots, and total laser energy in millijoules. All the patients will be treated with fluorometholone 0.1% eye drops QID for 5 days after surgery.
Data Collection: Laser treatment specifications will be noted for the amount in LPI positioning, number of applications, and amount of energy used. Other relevant patient information will also be noted such as best corrected visual acuity (BCVA), refractive error, IOP and presence of lens opacities along with the patients gender, age and ethnicity. These patients will be scheduled for follow up examination and IOP measurement at 2 weeks and 3 months after LPI procedure. On follow up a questionnaire will be given to patients assessing pain recollection and presence of dysphotopsias. Lid coverage of the LPI will also be noted.
Sample size and Justification:
The target sample size of 200 participants was selected to provide 80% power on an estimated incidence of 10.7% incidence of dysphotopsias after superior LPI versus 2.4% after temporal LPI with a 2-sided error at α = .05. This was based on the study published by Vera et al,.2014. The sample size allows for a 15% loss to follow-up and a 10% crossover between randomization groups.
Data Analysis: Group differences in baseline variables will be evaluated using Student t test for continuous variables and chi-square tests for categorical variables. P values of less than 0.05 will be considered statistically significant.
Recruitment: Patients will be identified on initial or follow up visits at Sunnybrook Health Center. The ophthalmologists will identify potential subjects and the study coordinator will explain the nature of the study and invite them to participate. An Information and Consent Form will be signed by the patient previous to the enrollment in the study.
- Conditions
- Primary Angle Glaucoma Closure Suspect
- Being tested
- Yag Laser peripheral Iridotomy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Yag Laser peripheral IridotomyProcedure or surgery
Laser peripheral iridotomy will be performed using neo-dynium:yttrium:aluminium-garnet laser after pretreatment with 2% pilocarpine and brimonidine 0.15%. Superior LPIs will be placed between the 11- and 1-o'clock positions such that they were covered completely by the upper eyelid; nasal/temporal LPIs will be placed between the 2- and 4-o'clock positions or the 8- and 10-o'clock positions such that they were completely clear of the lid margin. Preference will be given to iris crypts, avoiding iris vessels when possible. Laser peripheral iridotomies will be performed in both eyes during the same visit and will be confirmed to be patent after the procedure. Intraoperative data collected will include initial per-shot laser energy in milli joules, number of laser shots, and total laser energy in millijoules. All the patients will be treated with flurometholone 0.1% eye drops QID for 5 days after surgery.
| Study group | Role | What they receive |
|---|---|---|
| Superior LPI placement | Active comparator | Each participant will be randomized to receive an LPI placement superiorly in one eye. Receives: Procedure: Yag Laser peripheral Iridotomy |
| Temporal LPI placement | Active comparator | Each participant will be randomized to receive an LPI placement temporally in one eye. Receives: Procedure: Yag Laser peripheral Iridotomy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dysphotopsias noted from baseline visit before procedure till 3 months after procedure
We will inquire if patients experienced any of the following before and/or after the iridotomy: halo, lines, crescent, ghost image, glare, spots, shadows, blurring, or other unlisted visual disturbances. This will be part of the questionnaire completed before the procedure, at 2 weeks, and at 3 months.
Measured: 3 months from baseline visit
Secondary outcomes (1)
Pain during the baseline visit procedure and recollection of pain till 3 months after procedure
The pain during the procedure and recollection of pain in follow up study visits; (no pain is expected once the procedure is completed) is a secondary outcome, as part of the questionnaire, graded by a standardized pain scale grading the pain from 0 to 10, being 0 no pain and 10 the worst imaginable pain). This will be assessed immediately after the procedure, at 2 weeks and at 3 months after their laser peripheral iridotomy has been performed as is the current standard of care.
Measured: 3 months from baseline visit
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2021
- Study start25 Nov 2020
- Primary completion31 Dec 2023 (estimated)
- Study completion31 Dec 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Primary Angle Glaucoma Closure SuspectStudies 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
- Model description
- Each participant will be randomized to a specific LPI placement (superior or temporal) for one eye, and will be given the other alternative placement for the second eye. This is paired-eye comparative clinical trial.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Sunnybrook Health Sciences Centre
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Catherine Birt, Sunnybrook Health Sciences Centre
- Investigators
- Catherine Birt, MD, FRCSC, Principal investigator, Sunnybrook
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04741919
- Sponsor's protocol ID
- 3236_2020
- Status last verified
- Apr 2023
- First submitted
- 16 Oct 2020
- Last updated
- 11 Apr 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Apr 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized Prospective Study of Superior Versus Temporal Laser Peripheral Iridotomy (LPI) in Primary Angle Closure Suspects (PACS)
- ClinicalTrials.gov ID
- NCT04741919
- Acronym / sponsor ID
- 3236_2020
- Conditions
- Primary Angle Glaucoma Closure Suspect
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Sunnybrook Health Sciences CentreUniversity, hospital or other
- Study start
- 25 Nov 2020 (actual)
- Primary completion
- 31 Dec 2023 (estimated)
- Study completion
- 31 Dec 2024 (estimated)
- First posted
- 5 Feb 2021 (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.
Basic Study Design: Prospective, randomized, single-center, single-blinded study to compare dysphotopsias and pain recollection immediately 2 weeks, and 3 months after LPI in PACS patients who have a clear indication for bilateral LPI. Our null hypothesis is that there is no difference in dysphotopsia or pain levels by LPI position. Our alternate hypothesis is that there are more dysphotopsias superiorly and more pain temporally.
Detailed description
The study objective is to describe the difference in the incidence of dysphotopsias and sensation of pain both immediately, 2 weeks and 3 months after superior or temporal LPI. The main primary outcome variable will be the presence of dysphotopsias and the recollection of pain graded by a standardized pain scale.
Stratified Block Randomization: 200 patients will be recruited from participating centre. For each patient, the order of the eye to be treated as well as the position of the LPI superior or temporal will be randomized.
Methods:
Subjects: Patients included in the study will be patients referred for a glaucoma evaluation or in follow up at Sunnybrook Science Center who are diagnosed as PACS and have therefore an indication for bilateral LPIs.
Interventions: All patients eligible will be examined by the principal investigator, including a slit lamp assessment of the anterior segment, gonioscopy of the angle and stereoscopic optic nerve examination with a 78 Diopters lens. Intraocular pressure (IOP) will be measured with applanation tonometry. Patients will be assessed with a macular and optic nerve OCT to rule out glaucoma.
Only bilateral PACS patients will be included. One randomly selected eye will receive superior LPI while contralateral eye temporal LPI. At the 2 week and 3 month follow up visits patients will be asked about dysphotopsias in one or both eyes and their recollection of pain will be graded. Other distractors will be included in the questionnaire such as increased tearing sensation.
Laser peripheral iridotomy will be performed using neo-dynium:yttrium:aluminium-garnet laser after pretreatment with 2% pilocarpine and brimonidine 0.15%. Superior LPIs will be placed between the 11- and 1-o'clock positions such that they were covered completely by the upper eyelid; nasal/temporal LPIs will be placed between the 2- and 4-o'clock positions or the 8- and 10-o'clock positions such that they were completely clear of the lid margin. Preference will be given to iris crypts, avoiding iris vessels when possible. Laser peripheral iridotomies will be performed in both eyes during the same visit and will be confirmed to be patent after the procedure. Intraoperative data collected will include initial per-shot laser energy in milli joules, number of laser shots, and total laser energy in millijoules. All the patients will be treated with fluorometholone 0.1% eye drops QID for 5 days after surgery.
Data Collection: Laser treatment specifications will be noted for the amount in LPI positioning, number of applications, and amount of energy used. Other relevant patient information will also be noted such as best corrected visual acuity (BCVA), refractive error, IOP and presence of lens opacities along with the patients gender, age and ethnicity. These patients will be scheduled for follow up examination and IOP measurement at 2 weeks and 3 months after LPI procedure. On follow up a questionnaire will be given to patients assessing pain recollection and presence of dysphotopsias. Lid coverage of the LPI will also be noted.
Sample size and Justification:
The target sample size of 200 participants was selected to provide 80% power on an estimated incidence of 10.7% incidence of dysphotopsias after superior LPI versus 2.4% after temporal LPI with a 2-sided error at α = .05. This was based on the study published by Vera et al,.2014. The sample size allows for a 15% loss to follow-up and a 10% crossover between randomization groups.
Data Analysis: Group differences in baseline variables will be evaluated using Student t test for continuous variables and chi-square tests for categorical variables. P values of less than 0.05 will be considered statistically significant.
Recruitment: Patients will be identified on initial or follow up visits at Sunnybrook Health Center. The ophthalmologists will identify potential subjects and the study coordinator will explain the nature of the study and invite them to participate. An Information and Consent Form will be signed by the patient previous to the enrollment in the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Each participant will be randomized to a specific LPI placement (superior or temporal) for one eye, and will be given the other alternative placement for the second eye. This is paired-eye comparative clinical trial.
| Arm | Type | Receives |
|---|---|---|
| Superior LPI placement | Active comparator | Procedure: Yag Laser peripheral IridotomyEach participant will be randomized to receive an LPI placement superiorly in one eye. |
| Temporal LPI placement | Active comparator | Procedure: Yag Laser peripheral IridotomyEach participant will be randomized to receive an LPI placement temporally in one eye. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- clinical evidence of bilateral occludable angles (PACS) defined as:
- Peripheral anterior synechia (PAS) absent and trabecular meshwork not visible in ≥6 clock hours under non-indentation gonioscopy, Along with,
- absence of PAC or PACG, in both eyes.
- macular and optic nerve OCT within the 95% range of the normative database for patients to be included in this study.
Key exclusion criteria (4 listed)
- evidence of unilateral PACS,
- a history suggestive of an acute angle closure attack (based on symptoms) documented intraocular pressure over 30 mmHg,
- or any sign of Angle Closure Glaucoma (manifest glaucomatous neuropathy detected by OCT).
- Patients with previous ocular surgeries will also be excluded.
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 |
|---|---|---|
| Yag Laser peripheral IridotomyLaser peripheral iridotomy will be performed using neo-dynium:yttrium:aluminium-garnet laser after pretreatment with 2% pilocarpine and brimonidine 0.15%. Superior LPIs will be placed between the 11- and 1-o'clock positions such that they were covered completely by the upper eyelid; nasal/temporal LPIs will be placed between the 2- and 4-o'clock positions or the 8- and 10-o'clock positions such that they were completely clear of the lid margin. Preference will be given to iris crypts, avoiding iris vessels when possible. Laser peripheral iridotomies will be performed in both eyes during the same visit and will be confirmed to be patent after the procedure. Intraoperative data collected will include initial per-shot laser energy in milli joules, number of laser shots, and total laser energy in millijoules. All the patients will be treated with flurometholone 0.1% eye drops QID for 5 days after surgery. | Procedure or surgery | Superior LPI placement, Temporal LPI placement |
Primary outcome
Dysphotopsias noted from baseline visit before procedure till 3 months after procedure
Time frame: 3 months from baseline visit
We will inquire if patients experienced any of the following before and/or after the iridotomy: halo, lines, crescent, ghost image, glare, spots, shadows, blurring, or other unlisted visual disturbances. This will be part of the questionnaire completed before the procedure, at 2 weeks, and at 3 months.
1 secondary outcome
Pain during the baseline visit procedure and recollection of pain till 3 months after procedure
Time frame: 3 months from baseline visit
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Apr 2023.
- Individual participant dataSharing planned: No
Related trials for Primary Angle Glaucoma Closure Suspect
Recruiting
Danish Angle Closure Prevention Trial
Primary Angle Glaucoma Closure Suspect
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.
Catherine Birt, MD, FRCSC principal investigator
Sunnybrook
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Yag Laser peripheral Iridotomy in people with Primary Angle Glaucoma Closure Suspect, run by Sunnybrook Health Sciences Centre 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 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: status not confirmed, as of the sponsor's last update on 11 Apr 2023. 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.
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 Catherine Birt, MD, FRCSC (416-480-5882, catherine.birt@sunnybrook.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Dysphotopsias noted from baseline visit before procedure till 3 months after procedure (time frame: 3 months from baseline visit). 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 Apr 2023.