Comparison Between Two Techniques of Subthreshold Diode Laser Cyclophotocoagulation in Refractory Glaucoma
Primary Purpose
Refractory Glaucoma
Status
Not yet recruiting
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
360 degrees subthreshold diode laser cyclophotocoagulation
180 degrees subthreshold diode laser cyclophotocoagulation
Sponsored by
About this trial
This is an interventional treatment trial for Refractory Glaucoma
Eligibility Criteria
Inclusion Criteria:
- patients with refractory glaucoma (IOP > 21 mmHg unresponsive to maximally tolerated antiglaucoma medications, previously failed surgical treatment, or both)
Exclusion Criteria:
- Ocular inflammation.
- Ocular infection.
- Recent ocular surgery in the study eye in the 2 months prior to enrolment.
Sites / Locations
Arms of the Study
Arm 1
Arm 2
Arm Type
Active Comparator
Active Comparator
Arm Label
group A the standard technique
Group B a modified technique
Arm Description
cyclophotocoagulation is applied along the upper and lower hemispheres over pars plana -3 mm behind the limbus
cyclophotocoagulation is applied over one hemisphere only (180 degrees) along pars plana-3 mm behind the limbus- followed by a second application over pars plicata-1.2 mm behind the limbus- along the same hemisphere (ie, in a double arc fashion).
Outcomes
Primary Outcome Measures
IOP reduction success rate
Success rate is defined as achieving an IOP between 5 and 21 mmHg or at least a 20% reduction in IOP at the final follow up with or without IOP lowering medications
Secondary Outcome Measures
Full Information
1. Study Identification
Unique Protocol Identification Number
NCT05230355
Brief Title
Comparison Between Two Techniques of Subthreshold Diode Laser Cyclophotocoagulation in Refractory Glaucoma
Official Title
Comparison Between Two Techniques of Subthreshold Diode Laser Cyclophotocoagulation in Refractory Glaucoma
Study Type
Interventional
2. Study Status
Record Verification Date
January 2022
Overall Recruitment Status
Not yet recruiting
Study Start Date
February 1, 2022 (Anticipated)
Primary Completion Date
February 1, 2024 (Anticipated)
Study Completion Date
February 1, 2024 (Anticipated)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Assiut University
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No
5. Study Description
Brief Summary
The aim of this study is to assess the results of subliminal subthreshold transscleral diode cyclophotocoagulation in refractory glaucoma using the standard technique of 360 degree application and to compare the outcome with a modified technique both in terms of efficacy and safety.
Detailed Description
Refractory glaucoma is glaucoma that doesn't respond favorably to surgical and/or medical treatment to lower intraocular pressure. It can include primary open angle glaucoma, primary angle closure glaucoma, neovascular glaucoma or silicone oil-induced glaucoma. Cyclophotocoagulation (CPC) is a form 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. Transscleral cyclophotocoagulation using a continuous diode laser has been a treatment option in advanced glaucoma cases with s¬¬uboptimal IOP control, for a long time. High treatment energy used by diode laser cyclophotocoagulation was argued to be associated with increased frequency of serious complications such as vision loss, hypotony, and phthisis. These concerns necessitate modulation of the parameters of laser treatment used.
Micropulse transscleral cyclophotocoagulation (MP-TSCPC), which is a variation of conventional continuous-wave CPC, has emerged as an attractive alternative for the treatment of many types of glaucoma. It breaks the continuous wave laser into multiple short and repetitive pulses that allow the tissue to cool down between applications, thus reducing thermal damage. This strategy delivers very short energy pulses followed by rest periods, which is known as "duty cycle" and is defined as the ratio of time that a laser is delivering energy vs resting (ON/OFF). For this procedure, an infrared diode laser is used to stimulate the ciliary body structures and the uveoscleral pathway. This way it reduces the production of the aqueous humour and facilitates the uveoscleral outflow, with IOP reduction as a final effect.
Despite promising results, only few clinical studies are published on MP-TSCPC and most of them are retrospective studies refer to patients having previous continuous wave transscleral cyclophotocoagulation. Moreover, Several parameters and protocols have been studied in other reports in an attempt to refine the standard technique aiming to improve the outcomes without increasing the adverse effects.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Refractory Glaucoma
7. Study Design
Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
Participant
Allocation
Randomized
Enrollment
50 (Anticipated)
8. Arms, Groups, and Interventions
Arm Title
group A the standard technique
Arm Type
Active Comparator
Arm Description
cyclophotocoagulation is applied along the upper and lower hemispheres over pars plana -3 mm behind the limbus
Arm Title
Group B a modified technique
Arm Type
Active Comparator
Arm Description
cyclophotocoagulation is applied over one hemisphere only (180 degrees) along pars plana-3 mm behind the limbus- followed by a second application over pars plicata-1.2 mm behind the limbus- along the same hemisphere (ie, in a double arc fashion).
Intervention Type
Device
Intervention Name(s)
360 degrees subthreshold diode laser cyclophotocoagulation
Intervention Description
cyclophotocoagulation is applied along 360 degrees over pars plana
Intervention Type
Device
Intervention Name(s)
180 degrees subthreshold diode laser cyclophotocoagulation
Intervention Description
cyclophotocoagulation is applied over one hemisphere only along 180 degrees in a double arc fashion
Primary Outcome Measure Information:
Title
IOP reduction success rate
Description
Success rate is defined as achieving an IOP between 5 and 21 mmHg or at least a 20% reduction in IOP at the final follow up with or without IOP lowering medications
Time Frame
6 months
10. Eligibility
Sex
All
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria:
patients with refractory glaucoma (IOP > 21 mmHg unresponsive to maximally tolerated antiglaucoma medications, previously failed surgical treatment, or both)
Exclusion Criteria:
Ocular inflammation.
Ocular infection.
Recent ocular surgery in the study eye in the 2 months prior to enrolment.
12. IPD Sharing Statement
Plan to Share IPD
No
Learn more about this trial
Comparison Between Two Techniques of Subthreshold Diode Laser Cyclophotocoagulation in Refractory Glaucoma
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