GlaucomaNCT04709679
Laser Dosage in MicroPulse TransScleral CycloPhotocoagulation
A study testing MicroPulse TransScleral CycloPhotoCoagulation in people with Glaucoma, run by State University of New York at Buffalo at 1 site in United States.
Trial summary
This is a prospective study to evaluate the clinical outcome of varying doses of Micropulse TransScleral CycloPhotocoagulation (MP-TSCPC) laser in patients with glaucoma. The study will assess documented complication rates, changes in visual acuity after the procedure, changes in intraocular pressures and medication… Read more about this study
- Who is it for?
- Ages 18 to 89 years
- Conditions the study is for
- Glaucoma
- What is being tested?
- MicroPulse TransScleral CycloPhotoCoagulation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 6 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2021to 11 Oct 2021
- 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 to 89 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Decision to treat by MP-TSCPC Laser
- Patients diagnosed with Glaucoma
- Patients aged 18 years old and above
- Glaucoma that is inadequately controlled on medical therapy
- Patients with primary open angle glaucoma with or without previously failed trabeculectomy or other aqueous drainage surgical procedures
Who cannot join
- Patients age less than 18 years
- Patients unable or unwilling to provide informed consent to participate in the study
- Patients potentially unavailable for follow up visits
- Patients with significant scleral thinning
- Patients with ocular infection, inflammation or intraocular surgery in the study eye 2 months prior to enrollment in the study
- Albino patients that have no iris pigmentation
Trial locations and contacts
1 site in 1 country.
United States1 site
The Ira G. Ross Eye Institute
Buffalo, New York, 14209
About this study
Official title: Clinical Outcome of Varying Doses of Micropulse TransScleral CycloPhotocoagulation Laser in Patients With Glaucoma.
This is a prospective study to evaluate the clinical outcome of varying doses of Micropulse TransScleral CycloPhotocoagulation (MP-TSCPC) laser in patients with glaucoma. The study will assess documented complication rates, changes in visual acuity after the procedure, changes in intraocular pressures and medication drop usage, and need for subsequent treatments (including further laser or surgery).
Read the detailed description
Glaucoma is a condition where an increase in the accumulation of aqueous humor inside the anterior chamber of the eye results in raised intraocular pressure (IOP), visual field defects and cupping of optic disc. Typically, patients who have glaucoma are treated with topical medications or incisional surgery to lower the IOP. Micropulse transscleral cyclophotocoagulation (MP-TSCPC) is a non-incisional laser surgery used in the treatment of glaucoma. MP-TSCPC powered by the Cyclo G6 (Iridex Corporation, Mountain View, CA, USA) causes mild thermal damage to the ciliary body (gland that produces aqueous fluid in the eye), which, in turn, causes a decrease in intraocular pressure. MP-TSCPC is a variation of a longstanding older treatment for glaucoma, traditional diode TSCPC, which caused a significant amount of tissue damage and therefore was reserved for the treatment of end stage glaucoma.
The micropulse laser application includes an on-off cycle. In an on cycle, the micropulse probe administers a short pulse of laser energy followed by an off cycle which is a rest period for the tissue to cool off before the next on-off cycle begins. This corresponds to 0.5 ms duration of "on-time" and 1.1 ms interval of "off-time" during the laser application. This on-off cycle allows for the laser to treat the affected area without evidence of tissue damage, as opposed to the traditional diode TSCPC. Because only 31.3% of the total laser energy is applied to the ciliary body, there is a less tissue damage, less post-operative inflammation, and decreased complication rates. Therefore, MP-TSCPC is currently being utilized for milder cases of glaucoma, and in patients with viable vision. The laser probe is usually applied perpendicular to the limbus in a continuous sweeping motion, for an average of 10 seconds of sweeping time per hemifield, referred to as "dwell time". Therefore, the three parameters that can be varied in the treatment with MP-TSCPC are total laser duration (seconds), laser power (mW) and dwell time (seconds/hemifield).
Most of the studies used a laser power of 2000 - 2500 mW. The laser duration also has varied between studies. A duration time of 50 to 180 sec per hemisphere was used in different studies. Most studies have utilized a dwell time of 10 seconds per hemifield, and one cited an application of a "stop and go" method, applying the laser in discrete spots at 10 seconds each.
In all of the prior studies, despite the variable applications of power, dwell time, and duration, there have been similar rates of complications such as vision loss, macular edema, and hypotony. Generally, the laser duration is tailor-made and is adjusted based on the iris color and severity of glaucoma. However, there is a gap in knowledge on systematic comparison of different doses of MP-TSCPC for a safe and effective treatment of glaucoma. This study will systematically evaluate the clinical outcome of glaucoma surgery based on a logical variation of MP-TSCPC laser dosing parameters.
- Conditions
- Glaucoma
- Being tested
- MicroPulse TransScleral CycloPhotoCoagulation
- Keywords
- MP-TSCPC, Laser Duration, Laser Dwell time, Laser Power
- Medical subject headings
- Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MicroPulse TransScleral CycloPhotoCoagulationProcedure or surgery
A laser power of 2000- 2500 mW, a laser duration time of 50 to 80 sec per hemifield and varying da number of sweeps per hemifield 3, 4 or 5 will be randomized between patients
| Study group | Role | What they receive |
|---|---|---|
| Constant dwell time but varying power and duration | Experimental | The laser dwell time will be constant but the laser power and duration will be varied for patients Receives: Procedure: MicroPulse TransScleral CycloPhotoCoagulation |
| Constant power but varying dwell time and duration | Experimental | The laser power will be constant but the laser dwell time and duration will be varied for patients Receives: Procedure: MicroPulse TransScleral CycloPhotoCoagulation |
| Constant duration but varying dwell time and power | Experimental | The laser duration will be constant but the laser dwell time and power will be varied for patients Receives: Procedure: MicroPulse TransScleral CycloPhotoCoagulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in intraocular pressure measurements between baseline and postoperative followup visits
Baseline (pre-operative condition) and post operative intraocular pressure will be measured on Day1, Week1, Months 1, 3, 6, 12, 18 and 24.
Measured: 2years
Secondary outcomes (3)
Changes in visual acuity measurements measured using a Snellen Vision Chart between baseline and postoperative followup visits
Baseline (pre-operative condition) and post operative visual acuity will be measured on Day1, Week1, Months 1, 3, 6, 12, 18 and 24.
Measured: 2 years
Changes in number of medications between baseline and postoperative followup visits
Baseline (pre-operative condition) and post operative number of medications list will be measured on Day1, Week1, Months 1, 3, 6, 12, 18 and 24.
Measured: 2 years
Rate of post surgical complications
Rate of post surgical complications such as Hypotony, Corneal Edema, Hyphema, Iritis, Vitreous Hemorrhage and Cystoid Macular Edema.
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jan 2021
- Study start1 Jan 2021
- Primary completion11 Oct 2021
- Study completion11 Oct 2021
Why it stopped: Dose was not therapeudic
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.
- More trials run by State University of New York at BuffaloThe sponsor's other registered studies.
- 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
- 6 participants (actual)
Sponsor and investigators
- Lead sponsor
- State University of New York at Buffalo
- Sponsor type
- University, hospital or other
- Collaborators
- IRIDEX Corporation
- Responsible party
- Principal investigator, Sandra Sieminski, State University of New York at Buffalo
- Investigators
- Sandra F Sieminski, MD, Principal investigator, Ross Eye Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04709679
- Sponsor's protocol ID
- STUDY00003149
- Status last verified
- Jun 2022
- First submitted
- 12 Jan 2021
- Last updated
- 1 Jul 2022
- 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 1 Jul 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Clinical Outcome of Varying Doses of Micropulse TransScleral CycloPhotocoagulation Laser in Patients With Glaucoma.
- ClinicalTrials.gov ID
- NCT04709679
- Acronym / sponsor ID
- STUDY00003149
- Conditions
- Glaucoma
- Keywords
- MP-TSCPC, Laser Duration, Laser Dwell time, Laser Power
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Dose was not therapeudic
- Enrolment
- 6 participants (actual)
- Lead sponsor
- State University of New York at BuffaloUniversity, hospital or other
- Collaborators
- IRIDEX Corporation
- Study start
- 1 Jan 2021 (actual)
- Primary completion
- 11 Oct 2021 (actual)
- Study completion
- 11 Oct 2021 (actual)
- First posted
- 14 Jan 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.
This is a prospective study to evaluate the clinical outcome of varying doses of Micropulse TransScleral CycloPhotocoagulation (MP-TSCPC) laser in patients with glaucoma. The study will assess documented complication rates, changes in visual acuity after the procedure, changes in intraocular pressures and medication drop usage, and need for subsequent treatments (including further laser or surgery).
Detailed description
Glaucoma is a condition where an increase in the accumulation of aqueous humor inside the anterior chamber of the eye results in raised intraocular pressure (IOP), visual field defects and cupping of optic disc. Typically, patients who have glaucoma are treated with topical medications or incisional surgery to lower the IOP. Micropulse transscleral cyclophotocoagulation (MP-TSCPC) is a non-incisional laser surgery used in the treatment of glaucoma. MP-TSCPC powered by the Cyclo G6 (Iridex Corporation, Mountain View, CA, USA) causes mild thermal damage to the ciliary body (gland that produces aqueous fluid in the eye), which, in turn, causes a decrease in intraocular pressure. MP-TSCPC is a variation of a longstanding older treatment for glaucoma, traditional diode TSCPC, which caused a significant amount of tissue damage and therefore was reserved for the treatment of end stage glaucoma.
The micropulse laser application includes an on-off cycle. In an on cycle, the micropulse probe administers a short pulse of laser energy followed by an off cycle which is a rest period for the tissue to cool off before the next on-off cycle begins. This corresponds to 0.5 ms duration of "on-time" and 1.1 ms interval of "off-time" during the laser application. This on-off cycle allows for the laser to treat the affected area without evidence of tissue damage, as opposed to the traditional diode TSCPC. Because only 31.3% of the total laser energy is applied to the ciliary body, there is a less tissue damage, less post-operative inflammation, and decreased complication rates. Therefore, MP-TSCPC is currently being utilized for milder cases of glaucoma, and in patients with viable vision. The laser probe is usually applied perpendicular to the limbus in a continuous sweeping motion, for an average of 10 seconds of sweeping time per hemifield, referred to as "dwell time". Therefore, the three parameters that can be varied in the treatment with MP-TSCPC are total laser duration (seconds), laser power (mW) and dwell time (seconds/hemifield).
Most of the studies used a laser power of 2000 - 2500 mW. The laser duration also has varied between studies. A duration time of 50 to 180 sec per hemisphere was used in different studies. Most studies have utilized a dwell time of 10 seconds per hemifield, and one cited an application of a "stop and go" method, applying the laser in discrete spots at 10 seconds each.
In all of the prior studies, despite the variable applications of power, dwell time, and duration, there have been similar rates of complications such as vision loss, macular edema, and hypotony. Generally, the laser duration is tailor-made and is adjusted based on the iris color and severity of glaucoma. However, there is a gap in knowledge on systematic comparison of different doses of MP-TSCPC for a safe and effective treatment of glaucoma. This study will systematically evaluate the clinical outcome of glaucoma surgery based on a logical variation of MP-TSCPC laser dosing parameters.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Constant dwell time but varying power and duration | Experimental | Procedure: MicroPulse TransScleral CycloPhotoCoagulationThe laser dwell time will be constant but the laser power and duration will be varied for patients |
| Constant power but varying dwell time and duration | Experimental | Procedure: MicroPulse TransScleral CycloPhotoCoagulationThe laser power will be constant but the laser dwell time and duration will be varied for patients |
| Constant duration but varying dwell time and power | Experimental | Procedure: MicroPulse TransScleral CycloPhotoCoagulationThe laser duration will be constant but the laser dwell time and power will be varied for patients |
Who may qualify
- Ages
- 18 to 89 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Decision to treat by MP-TSCPC Laser
- Patients diagnosed with Glaucoma
- Patients aged 18 years old and above
- Glaucoma that is inadequately controlled on medical therapy
- Patients with primary open angle glaucoma with or without previously failed trabeculectomy or other aqueous drainage surgical procedures
Key exclusion criteria (6 listed)
- Patients age less than 18 years
- Patients unable or unwilling to provide informed consent to participate in the study
- Patients potentially unavailable for follow up visits
- Patients with significant scleral thinning
- Patients with ocular infection, inflammation or intraocular surgery in the study eye 2 months prior to enrollment in the study
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 |
|---|---|---|
| MicroPulse TransScleral CycloPhotoCoagulationA laser power of 2000- 2500 mW, a laser duration time of 50 to 80 sec per hemifield and varying da number of sweeps per hemifield 3, 4 or 5 will be randomized between patients | Procedure or surgery | Constant duration but varying dwell time and power, Constant dwell time but varying power and duration, Constant power but varying dwell time and duration |
Primary outcome
Changes in intraocular pressure measurements between baseline and postoperative followup visits
Time frame: 2years
Baseline (pre-operative condition) and post operative intraocular pressure will be measured on Day1, Week1, Months 1, 3, 6, 12, 18 and 24.
3 secondary outcomes
Changes in visual acuity measurements measured using a Snellen Vision Chart between baseline and postoperative followup visits
Time frame: 2 years
Changes in number of medications between baseline and postoperative followup visits
Time frame: 2 years
Rate of post surgical complications
Time frame: 2 years
Results and safety
The study was stopped early (reason given: Dose was not therapeudic). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Jul 2022.
- Individual participant dataSharing planned: No
Related trials for Glaucoma
Recruiting
Automated Applanation Tonometry - Updated
Glaucoma, Glaucoma, Suspect
Recruiting
Brain Stimulation Effects on Orientation and Mobility Skills in Adults With Vision Impairment
Retinitis Pigmentosa (RP), Rod Cone Dystrophy
RecruitingPhase 2
A Phase 2a Study Comparing the Efficacy, Safety and Tolerability of Pregabalin Eye Drops Comparing With Timolol Eye Drops in Adults With Glaucoma or High Eye Pressure.
Primary Open - Angle Glaucoma (POAG), Ocular Hypertension (OHT)
Recruiting
Effects of Balance Training in Individuals With Glaucoma
Glaucoma
Not yet recruiting
Glaucoma Drop Aids Part 2
Glaucoma, Intraocular Pressure
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.
Sandra F Sieminski, MD principal investigator
Ross Eye Institute
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing MicroPulse TransScleral CycloPhotoCoagulation in people with Glaucoma, run by State University of New York at Buffalo at 1 site in United States.
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 6 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: stopped early, as of the sponsor's last update on 1 Jul 2022. 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 United States. 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?
The study was stopped early (reason given: Dose was not therapeudic). Results are not available in the source record.
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?
Changes in intraocular pressure measurements between baseline and postoperative followup visits (time frame: 2years). 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 1 Jul 2022; AzTrials last refreshed its copy on 4 Nov 2026.