Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation in Uncontrolled Glaucoma

September 13, 2021 updated by: Centre hospitalier de l'Université de Montréal (CHUM)

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

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Actual)

52

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Quebec
      • Montréal, Quebec, Canada, H2X 3E4
        • Centre hospitalier de l'Université de Montréal (CHUM)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
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 Names:
  • CYCLO G6 Glaucoma Laser System (Iridex, Mountain View, CA)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Intraocular Pressure (IOP)
Time Frame: 18 months
In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer
18 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
1 week, 1 month, 3 months, 6 months, 12 months
Number of Participants With Repeat Treatments
Time Frame: 18 months
Number of participants needing a repeat laser treatment during the study
18 months
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
1 week, 1 month, 3 months, 6 months, 12 months, 18 months
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
1 week, 1 month, 3 months, 6 months, 12 months, 18 months
Cup-to-disc Ratio (CDR)
Time Frame: 18 months
Progression of CDR compared to baseline, assessed by an ophthalmologist on dilated fundus examination
18 months
Visual Field Index (VFI)
Time Frame: 18 months
Determined by Humphrey automated perimetry Sita 24-2 visual field testing
18 months
Mean Deviation (MD)
Time Frame: 18 months
Determined by Humphrey automated perimetry Sita 24-2 visual field testing
18 months
Pattern Standard Deviation (PSD)
Time Frame: 18 months
Determined by Humphrey automated perimetry Sita 24-2 visual field testing
18 months
Average Retinal Nerve Fiber Layer (RNFL) Thickness
Time Frame: 18 months
In micrometer, determined by optical coherence tomography (OCT)
18 months
Average Ganglion Cell Layer (GCL) Thickness
Time Frame: 18 months
In micrometer, determined by optical coherence tomography (OCT)
18 months
Cup-to-disc Ratio (CDR) Assessed by Optical Coherence Tomography (OCT)
Time Frame: 18 months
Progression of vertical CDR compared to baseline, assessed by optical coherence tomography (OCT) parameters
18 months
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)
1 day

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centre hospitalier de l'Université de Montréal (CHUM)

Investigators

  • 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)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 19, 2017

Primary Completion (Actual)

February 15, 2020

Study Completion (Actual)

February 15, 2020

Study Registration Dates

First Submitted

June 12, 2017

First Submitted That Met QC Criteria

June 12, 2017

First Posted (Actual)

June 15, 2017

Study Record Updates

Last Update Posted (Actual)

October 8, 2021

Last Update Submitted That Met QC Criteria

September 13, 2021

Last Verified

August 1, 2020

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CE16.351

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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