Cyclophotocoagulation in Glaucoma

Study Overview
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Brief Summary
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Transscleral cyclophotocoagulation of the ciliary body is an effective technique to reduce intraocular pressure in case of glaucoma. Due to concerns over complications, the main indications for this second-line treatment are refractory glaucoma medication / surgery and low visual prognosis. The 2000 milliwatts (mW) for 2 seconds settings are used by the majority of researchers and clinicians according to the published literature. Some have proposed using 1250 mW for 4 seconds to improve the use of this medical procedure. The aim of this study is to determine how different parameters affect the efficacy of the treatment. This is a prospective double-blinded randomized controlled trial comparing two groups, the experimental group using 1250 mW for 4 seconds and the control group using 2000 mW for 2 seconds.

Official Title
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Modified Settings for Transscleral Cyclophotocoagulation of the Ciliary Body in Glaucoma : A Randomized Controlled Trial

Conditions
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Glaucoma

Intervention / Treatment
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* Procedure: Cyclophotocoagulation protocol
* Procedure: Conventional cyclophotocoagulation
* Procedure: Modified cyclophotocoagulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with poorly controlled high pressure glaucoma Cyclophotocoagulation necessary to prevent visual loss Cyclophotocoagulation necessary to prevent or to reduce ocular discomfort Exclusion Criteria: Patient has already undergone a cyclophotocoagulation or cryotherapy treatment in the same eye for glaucoma Patients receiving concomitant treatment the same day as the intervention Patient not able to follow the prescribed post-operative treatment

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Diode laser using conventional settings<br>The cyclophotocoagulation protocol is used with the conventional cyclophotocoagulation settings of 2000 mW for 2 seconds. | Procedure: Cyclophotocoagulation protocol<br>* Intravenous route is installed Retrobulbar anaesthesia : 50% xylocaine (2%) + 50% bupivicaine Parameters set for laser treatment (1250mW-4seconds or 2000mW-2 seconds depending on the assigned group) Pars plana measurement using transillumination (if needed) Laser treatment applied approximately 1mm post to limbus Dexamethasone 0,5 mg subconjunctival injection Post-op regimen: Prednisolone 1% qid x 4 weeks, Atropine 1% bid x 2 weeks + Erythromycin ointment + patch x 6h<br>Procedure: Conventional cyclophotocoagulation<br>* 1250 mW for 4 seconds.<br>|
| Experimental: Diode laser using modified settings<br>The cyclophotocoagulation protocol is used with the modified cyclophotocoagulation settings of 1250 mW for 4 seconds. | Procedure: Cyclophotocoagulation protocol<br>* Intravenous route is installed Retrobulbar anaesthesia : 50% xylocaine (2%) + 50% bupivicaine Parameters set for laser treatment (1250mW-4seconds or 2000mW-2 seconds depending on the assigned group) Pars plana measurement using transillumination (if needed) Laser treatment applied approximately 1mm post to limbus Dexamethasone 0,5 mg subconjunctival injection Post-op regimen: Prednisolone 1% qid x 4 weeks, Atropine 1% bid x 2 weeks + Erythromycin ointment + patch x 6h<br>Procedure: Modified cyclophotocoagulation<br>* 2000 mW for 2 seconds.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intraocular pressure (IOP) evolution | The intraocular pressure is measured to determine the efficacy of treatment during follow-up compared to the baseline IOP. | 1h, 1 month, 6 months, 12 months, 18 months and 24 months post-op | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Presence of complications | Assessment of complications (if applicable). | During the intervention, 1 month, 6 months, 12 months, 18 months, 24 months post-op | 
| Use of medication | Assessment of the topical and oral glaucoma medication at baseline and after treatment | 1 month, 6 months, 12 months, 18 months and 24 months post-op | 
| Retreatment | The clinician will assess the need for retreatment based on clinical experience. | From the initial treatment up to the last visit (24 months) | 
| Visual acuity | The visual acuity will be assessed at baseline and each subsequent visit | 1 month, 6 months, 12 months, 18 months and 24 months post-op |