Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation in Uncontrolled Glaucoma

Glaucoma Clinical Trial

Official title:

Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation (mTSCPC) in Uncontrolled Glaucoma at the University of Montreal Hospital Center (CHUM)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03187418
• Other study ID #: CE16.351
• Status: Completed
• Phase: N/A
• Start date: June 19, 2017
• Est. completion date: February 15, 2020

Study information

• Verified date: August 2020
• Source: Centre hospitalier de l'Université de Montréal (CHUM)
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 52
• Est. completion date: February 15, 2020
• Est. primary completion date: February 15, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

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.

Related Conditions & MeSH terms

• Glaucoma
• Glaucoma and Ocular Hypertension
• Glaucoma Eye
• Glaucoma Secondary
• Glaucoma, Angle-Closure
• Glaucoma, Neovascular
• Glaucoma, Open-Angle
• Glaucoma, Uncompensated
• Ocular Hypertension

Intervention

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).

Locations

Country	Name	City	State
Canada	Centre Hospitalier de l'Université de Montréal (CHUM)	Montréal	Quebec

Sponsors (1)

Lead Sponsor	Collaborator
Centre hospitalier de l'Université de Montréal (CHUM)

Country where clinical trial is conducted

Canada, 

References & Publications (28)

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* Note: There are 28 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Intraocular Pressure (IOP)	In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer	18 months
Secondary	Intraocular Pressure (IOP)	In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer	1 week, 1 month, 3 months, 6 months, 12 months
Secondary	Number of Participants With Repeat Treatments	Number of participants needing a repeat laser treatment during the study	18 months
Secondary	Number of Intraocular Pressure Lowering Medications	Number of drops and oral medications used by the patient compared to baseline	1 week, 1 month, 3 months, 6 months, 12 months, 18 months
Secondary	Corrected Distance Visual Acuity (CDVA)	Number of lines reduction or improvement from baseline on Snellen acuity chart at 6 meters	1 week, 1 month, 3 months, 6 months, 12 months, 18 months
Secondary	Cup-to-disc Ratio (CDR)	Progression of CDR compared to baseline, assessed by an ophthalmologist on dilated fundus examination	18 months
Secondary	Visual Field Index (VFI)	Determined by Humphrey automated perimetry Sita 24-2 visual field testing	18 months
Secondary	Mean Deviation (MD)	Determined by Humphrey automated perimetry Sita 24-2 visual field testing	18 months
Secondary	Pattern Standard Deviation (PSD)	Determined by Humphrey automated perimetry Sita 24-2 visual field testing	18 months
Secondary	Average Retinal Nerve Fiber Layer (RNFL) Thickness	In micrometer, determined by optical coherence tomography (OCT)	18 months
Secondary	Average Ganglion Cell Layer (GCL) Thickness	In micrometer, determined by optical coherence tomography (OCT)	18 months
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	18 months
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)	1 day