Glaucoma, Glaucoma and Ocular Hypertension, Glaucoma Eye, Glaucoma, Neovascular, Glaucoma, Open-Angle, Glaucoma Secondary, Glaucoma, Uncompensated
Conditions
Keywords
Cyclophotocoagulation, Micropulse TSCPC, Laser ablation, Laser therapy
Brief summary
The goal of this study is to evaluate the efficacy and safety of the novel form of trans-scleral cyclophotocoagulation using micropulse diode laser and trans-pars plana treatment (Micropulse TSCPC, mTSCPC MP3, IRIDEX CYCLO G6™ Glaucoma Laser System, CA, USA) in adults for the treatment of uncontrolled glaucoma.
Detailed description
Cyclophotocoagulation (CPC) is a type of cycloablation using laser to treat glaucoma. It involves ciliary body destruction by targeting the ciliary epithelium and stroma, resulting in a reduction in aqueous secretion and hence intraocular pressure. This strategy is effective for all forms of glaucoma. Traditional trans-scleral cyclophotocoagulation (TSCPC) achieve its cyclodestructive action by using continuous diode laser to target the melanin in the pigmented ciliary body epithelium. However, the continuous mode has been shown to cause significant collateral tissue damage to adjacent non-pigmented structures including the ciliary stroma and ciliary muscle. Traditional TSCPC may therefore be associated with serious complications including uveitis, visual deterioration, chronic hypotony, and others. More recently, a micropulse delivery mode of diode laser (Micropulse TSCPC, mTSCPC) has been used to treat glaucoma by ablating the ciliary processes and reduce aqueous humor production with more selective targeting and less collateral damage. In contrast to conventional laser delivery where a continuous flow of high intensity energy is delivered, micropulse laser application delivers a series of repetitive short pulses of energy with rest periods in between pulses. Only a few studies have described the outcomes of this novel glaucoma therapy, showing mTSCPC to have comparable efficacy with fewer side effects when compared with traditional continuous wave mode diode laser delivery.This improved side effect profile has the potential to make mTSCPC an earlier therapeutic option instead of reserving it exclusively for end-stage refractory eyes.
Interventions
DEVICEMicroPulse® P3 Glaucoma Device (MP3)
Laser settings will be programmed as follows: power-2000mW-2500mW (average 2000mW) of 810nm infrared diode laser set on micropulse delivery mode; micropulse on time-0.5ms; micropulse off time-1.1ms; and duty cycle (proportion of each cycle during which the laser is on)-31.33 %. The laser probe will be applied in a continuous sliding or painting motion from 9:30 to 2:30 and from 3:30 to 8:30. The probe will be applied perpendicular to the limbus with the edge directly on the limbus at all times (fiberoptic tip at 3 mm posterior to the limbus). The laser will be delivered over 360° for 160-320s. Treatment duration will be adjusted based on iris color and glaucoma severity (mild glaucoma: 160s, moderate glaucoma: 240s, advanced glaucoma: 240-320s).
Sponsors
Centre hospitalier de l'Université de Montréal (CHUM)
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Prospective, interventional and monocentric study based in a university hospital setting
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Patients of either sex and any race aged 18 years old and above. * Followed by a glaucoma subspecialist at University of Montreal Hospital Center. * Intraocular pressure (IOP) above target and unresponsive to maximal tolerated medical therapy with or without previous surgical intervention. 1. mild glaucoma: IOP \> 18 mmHg 2. moderate glaucoma: IOP \> 15 mmHg 3. advanced glaucoma: IOP \> 12 mmHg * Considered poor candidates for additional filtering surgery or implantation of glaucoma drainage devices.
Exclusion criteria
* Patients unable to give informed consent. * Patients with significant scleral thinning, defined as thinning of more than one clock hour noticed on scleral transillumination. * Ocular infection or inflammation in the study eye in the 2 months prior to enrolment. * Intraocular surgery in the study eye in the 2 months prior to enrolment.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Intraocular Pressure (IOP) | 18 months | In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Repeat Treatments | 18 months | Number of participants needing a repeat laser treatment during the study |
| Number of Intraocular Pressure Lowering Medications | 1 week, 1 month, 3 months, 6 months, 12 months, 18 months | Number of drops and oral medications used by the patient compared to baseline |
| Corrected Distance Visual Acuity (CDVA) | 1 week, 1 month, 3 months, 6 months, 12 months, 18 months | Number of lines reduction or improvement from baseline on Snellen acuity chart at 6 meters |
| Cup-to-disc Ratio (CDR) | 18 months | Progression of CDR compared to baseline, assessed by an ophthalmologist on dilated fundus examination |
| Visual Field Index (VFI) | 18 months | Determined by Humphrey automated perimetry Sita 24-2 visual field testing |
| Intraocular Pressure (IOP) | 1 week, 1 month, 3 months, 6 months, 12 months | In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer |
| Pattern Standard Deviation (PSD) | 18 months | Determined by Humphrey automated perimetry Sita 24-2 visual field testing |
| Average Retinal Nerve Fiber Layer (RNFL) Thickness | 18 months | In micrometer, determined by optical coherence tomography (OCT) |
| Average Ganglion Cell Layer (GCL) Thickness | 18 months | In micrometer, determined by optical coherence tomography (OCT) |
| Cup-to-disc Ratio (CDR) Assessed by Optical Coherence Tomography (OCT) | 18 months | Progression of vertical CDR compared to baseline, assessed by optical coherence tomography (OCT) parameters |
| Pain Level During Laser Treatment | 1 day | Using a verbal analog scale for pain level (none = no subjective feeling of pain, mild = pain easily tolerable, moderate = pain tolerable with difficulty, severe = pain intolerable) |
| Mean Deviation (MD) | 18 months | Determined by Humphrey automated perimetry Sita 24-2 visual field testing |
Countries
Canada
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Micropulse Trans-scleral CPC A treatment session of micropulse trans-scleral cyclophotocoagulation in the affected eye, using the MicroPulse® P3 Glaucoma Device (MP3) powered by the CYCLO G6™ Glaucoma Laser System (Iridex, Mountain View, CA, USA).
MicroPulse® P3 Glaucoma Device (MP3): Laser settings will be programmed as follows: power-2000mW-2500mW (average 2000mW) of 810nm infrared diode laser set on micropulse delivery mode; micropulse on time-0.5ms; micropulse off time-1.1ms; and duty cycle (proportion of each cycle during which the laser is on)-31.33 %.
The laser probe will be applied in a continuous sliding or painting motion from 9:30 to 2:30 and from 3:30 to 8:30. The probe will be applied perpendicular to the limbus with the edge directly on the limbus at all times (fiberoptic tip at 3 mm posterior to the limbus).
The laser will be delivered over 360° for 160-320s. Treatment duration will be adjusted based on iris color and glaucoma severity (mild glaucoma: 160s, moderate glaucoma: 240s, advanced glaucoma: 240-320s). | 52 |
| Total | 52 |
Baseline characteristics
| Characteristic | Micropulse Trans-scleral CPC |
|---|---|
| Age, Continuous | 69 years STANDARD_DEVIATION 14 |
| Glaucoma diagnosis Chronic primary angle-closure glaucoma | 3 Participants |
| Glaucoma diagnosis Combined mechanism glaucoma | 1 Participants |
| Glaucoma diagnosis Congenital/infantile glaucoma | 4 Participants |
| Glaucoma diagnosis Neovascular glaucoma | 5 Participants |
| Glaucoma diagnosis Normotensive glaucoma | 1 Participants |
| Glaucoma diagnosis Other secondary glaucoma | 2 Participants |
| Glaucoma diagnosis Pigmentary glaucoma | 3 Participants |
| Glaucoma diagnosis Primary open angle glaucoma | 28 Participants |
| Glaucoma diagnosis Pseudoexfoliative glaucoma | 4 Participants |
| Glaucoma diagnosis Uveitic/inflammatory glaucoma | 1 Participants |
| Glaucoma severity Advanced | 35 Participants |
| Glaucoma severity Mild | 1 Participants |
| Glaucoma severity Moderate | 16 Participants |
| Race/Ethnicity, Customized African American | 6 Participants |
| Race/Ethnicity, Customized Asian | 2 Participants |
| Race/Ethnicity, Customized Caucasian | 41 Participants |
| Race/Ethnicity, Customized Middle East | 3 Participants |
| Region of Enrollment Canada | 52 participants |
| Sex: Female, Male Female | 26 Participants |
| Sex: Female, Male Male | 26 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 52 |
| other Total, other adverse events | 0 / 52 |
| serious Total, serious adverse events | 0 / 52 |
Outcome results
Primary
Intraocular Pressure (IOP)
In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Intraocular Pressure (IOP) | 15.2 millimeters of mercury (mm Hg) | Standard Deviation 4.1 |
Secondary
Average Ganglion Cell Layer (GCL) Thickness
In micrometer, determined by optical coherence tomography (OCT)
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Average Ganglion Cell Layer (GCL) Thickness | 53 micrometers | Standard Deviation 14 |
Secondary
Average Retinal Nerve Fiber Layer (RNFL) Thickness
In micrometer, determined by optical coherence tomography (OCT)
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Average Retinal Nerve Fiber Layer (RNFL) Thickness | 62 micrometers | Standard Deviation 12 |
Secondary
Corrected Distance Visual Acuity (CDVA)
Number of lines reduction or improvement from baseline on Snellen acuity chart at 6 meters
Time frame: 1 week, 1 month, 3 months, 6 months, 12 months, 18 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Micropulse Trans-scleral CPC | Corrected Distance Visual Acuity (CDVA) | 1 week | 0.81 LogMAR | Standard Deviation 0.86 |
| Micropulse Trans-scleral CPC | Corrected Distance Visual Acuity (CDVA) | 1 month | 0.84 LogMAR | Standard Deviation 0.9 |
| Micropulse Trans-scleral CPC | Corrected Distance Visual Acuity (CDVA) | 3 months | 0.79 LogMAR | Standard Deviation 0.88 |
| Micropulse Trans-scleral CPC | Corrected Distance Visual Acuity (CDVA) | 6 months | 0.77 LogMAR | Standard Deviation 0.86 |
| Micropulse Trans-scleral CPC | Corrected Distance Visual Acuity (CDVA) | 12 months | 0.79 LogMAR | Standard Deviation 0.86 |
| Micropulse Trans-scleral CPC | Corrected Distance Visual Acuity (CDVA) | 18 months | 0.82 LogMAR | Standard Deviation 0.88 |
Secondary
Cup-to-disc Ratio (CDR)
Progression of CDR compared to baseline, assessed by an ophthalmologist on dilated fundus examination
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Cup-to-disc Ratio (CDR) | 0.82 ratio | Standard Deviation 0.13 |
Secondary
Cup-to-disc Ratio (CDR) Assessed by Optical Coherence Tomography (OCT)
Progression of vertical CDR compared to baseline, assessed by optical coherence tomography (OCT) parameters
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Cup-to-disc Ratio (CDR) Assessed by Optical Coherence Tomography (OCT) | 0.82 ratio | Standard Deviation 0.13 |
Secondary
Intraocular Pressure (IOP)
In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer
Time frame: 1 week, 1 month, 3 months, 6 months, 12 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Micropulse Trans-scleral CPC | Intraocular Pressure (IOP) | 1 week | 18.2 millimeters of mercury (mm Hg) | Standard Deviation 6.3 |
| Micropulse Trans-scleral CPC | Intraocular Pressure (IOP) | 1 month | 19.2 millimeters of mercury (mm Hg) | Standard Deviation 7.4 |
| Micropulse Trans-scleral CPC | Intraocular Pressure (IOP) | 3 months | 18.6 millimeters of mercury (mm Hg) | Standard Deviation 6.2 |
| Micropulse Trans-scleral CPC | Intraocular Pressure (IOP) | 6 months | 17.9 millimeters of mercury (mm Hg) | Standard Deviation 5.3 |
| Micropulse Trans-scleral CPC | Intraocular Pressure (IOP) | 12 months | 16.7 millimeters of mercury (mm Hg) | Standard Deviation 5.6 |
Secondary
Mean Deviation (MD)
Determined by Humphrey automated perimetry Sita 24-2 visual field testing
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Mean Deviation (MD) | -15.16 decibel (dB) | Standard Deviation 7.72 |
Secondary
Number of Intraocular Pressure Lowering Medications
Number of drops and oral medications used by the patient compared to baseline
Time frame: 1 week, 1 month, 3 months, 6 months, 12 months, 18 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Micropulse Trans-scleral CPC | Number of Intraocular Pressure Lowering Medications | 1 week | 3.5 glaucoma medication classes | Standard Deviation 0.7 |
| Micropulse Trans-scleral CPC | Number of Intraocular Pressure Lowering Medications | 1 month | 3.4 glaucoma medication classes | Standard Deviation 0.8 |
| Micropulse Trans-scleral CPC | Number of Intraocular Pressure Lowering Medications | 3 months | 3.4 glaucoma medication classes | Standard Deviation 0.9 |
| Micropulse Trans-scleral CPC | Number of Intraocular Pressure Lowering Medications | 6 months | 3.4 glaucoma medication classes | Standard Deviation 0.8 |
| Micropulse Trans-scleral CPC | Number of Intraocular Pressure Lowering Medications | 12 months | 3.2 glaucoma medication classes | Standard Deviation 0.9 |
| Micropulse Trans-scleral CPC | Number of Intraocular Pressure Lowering Medications | 18 months | 3.2 glaucoma medication classes | Standard Deviation 0.9 |
Secondary
Number of Participants With Repeat Treatments
Number of participants needing a repeat laser treatment during the study
Time frame: 18 months
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Micropulse Trans-scleral CPC | Number of Participants With Repeat Treatments | 10 Participants |
Secondary
Pain Level During Laser Treatment
Using a verbal analog scale for pain level (none = no subjective feeling of pain, mild = pain easily tolerable, moderate = pain tolerable with difficulty, severe = pain intolerable)
Time frame: 1 day
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Pain Level During Laser Treatment | None | 34 Participants |
| Micropulse Trans-scleral CPC | Pain Level During Laser Treatment | Mild | 12 Participants |
| Micropulse Trans-scleral CPC | Pain Level During Laser Treatment | Moderate | 6 Participants |
| Micropulse Trans-scleral CPC | Pain Level During Laser Treatment | Severe | 0 Participants |
Secondary
Pattern Standard Deviation (PSD)
Determined by Humphrey automated perimetry Sita 24-2 visual field testing
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Pattern Standard Deviation (PSD) | 7.87 decibel (dB) | Standard Deviation 3.18 |
Secondary
Visual Field Index (VFI)
Determined by Humphrey automated perimetry Sita 24-2 visual field testing
Time frame: 18 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Micropulse Trans-scleral CPC | Visual Field Index (VFI) | 57 percents | Standard Deviation 27 |