Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation in Uncontrolled Glaucoma
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|ClinicalTrials.gov Identifier: NCT03187418|
Recruitment Status : Active, not recruiting
First Posted : June 15, 2017
Last Update Posted : February 12, 2019
|Condition or disease||Intervention/treatment||Phase|
|Glaucoma Glaucoma, Open-Angle Glaucoma, Neovascular Glaucoma and Ocular Hypertension Glaucoma Eye Glaucoma, Uncompensated Glaucoma Secondary||Device: MicroPulse® P3 Glaucoma Device (MP3)||Not Applicable|
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.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||52 participants|
|Intervention Model:||Single Group Assignment|
|Intervention Model Description:||Prospective, interventional and monocentric study based in a university hospital setting|
|Masking:||None (Open Label)|
|Official Title:||Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation (mTSCPC) in Uncontrolled Glaucoma at the University of Montreal Hospital Center (CHUM)|
|Actual Study Start Date :||June 19, 2017|
|Estimated Primary Completion Date :||February 2019|
|Estimated Study Completion Date :||March 2019|
Experimental: 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).
Device: 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).
Other Name: CYCLO G6 Glaucoma Laser System (Iridex, Mountain View, CA)
- Intraocular pressure (IOP) [ Time Frame: 18 months ]In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer
- Intraocular pressure (IOP) [ Time Frame: 1 week, 1 month, 3 months, 6 months, 12 months ]In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer
- Number of repeat treatments [ Time Frame: 18 months ]Number of necessary laser treatment repeats during the study
- Number of intraocular pressure lowering medications [ Time Frame: 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) [ Time Frame: 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) [ Time Frame: 1 week, 1 month, 3 months, 6 months, 12 months, 18 months ]Progression of CDR compared to baseline, assessed by an ophthalmologist on dilated fundus examination
- Visual field index (VFI) [ Time Frame: 18 months ]Determined by Humphrey automated perimetry Sita 24-2 visual field testing
- Mean deviation (MD) [ Time Frame: 18 months ]Determined by Humphrey automated perimetry Sita 24-2 visual field testing
- Pattern standard deviation (PSD) [ Time Frame: 18 months ]Determined by Humphrey automated perimetry Sita 24-2 visual field testing
- Glaucoma hemifield test (GHT) [ Time Frame: 18 months ]Determined by Humphrey automated perimetry Sita 24-2 visual field testing
- Average retinal nerve fiber layer (RNFL) thickness [ Time Frame: 18 months ]In micrometer, determined by optical coherence tomography (OCT)
- Average ganglion cell layer (GCL) thickness [ Time Frame: 18 months ]In micrometer, determined by optical coherence tomography (OCT)
- Cup-to-disc ratio (CDR) [ Time Frame: 18 months ]Progression of vertical CDR compared to baseline, assessed by optical coherence tomography (OCT) parameters
- Pain level during laser treatment [ Time Frame: 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)
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03187418
|Centre Hospitalier de l'Université de Montréal (CHUM)|
|Montréal, Quebec, Canada, H2X 3E4|
|Principal Investigator:||Harmanjit Singh, MD||Centre hospitalier de l'Université de Montréal (CHUM)|
|Principal Investigator:||Michael Marchand, MD||Centre hospitalier de l'Université de Montréal (CHUM)|