Panretinal Photocoagulation for Diabetic Retinopathy With PASCAL Laser

Study Overview
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Brief Summary
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This study will investigate the clinical efficacy and safety of the PASCAL laser (PAttern SCAn Laser) for diabetic retinopathy. Patients with proliferative or severe nonproliferative retinopathy will be treated with panretinal photocoagulation utilizing different treatment strategies. The investigators believe that using lower laser parameters, the clinical response may be equivalent with less adverse effects.

Official Title
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Panretinal Photocoagulation for Diabetic Retinopathy With PASCAL Laser - an Anatomic and Functional Evaluation of Different Treatment Strategies

Conditions
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Diabetic Retinopathy

Intervention / Treatment
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* Procedure: Panretinal photocoagulation
* Procedure: Panretinal photocoagulation
* Procedure: Panretinal photocoagulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: proliferative or severe nonproliferative diabetic retinopathy (type 1 or type 2) best corrected visual acuity of 20/50 or better capability to read and follow instructions capability to sign the consignment term Exclusion Criteria: best corrected visual acuity worse than 20/50 significant macular edema responsible for visual acuity lower than 20/50 media opacities (includes vitreous hemorrhage in the visual axis, but not a reabsorbing inferior vitreous hemorrhage) previous laser treatment (PRP, focal or macular grid) glaucoma (confirmed or suspicious) other diseases of the retina and optic nerve previous ocular surgery in the last 6 months impossibility to obtain good quality images of retinography, angiography or OCT

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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No

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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 100ms single-shot<br>Panretinal photocoagulation utilizing 100ms pulse duration, moderate intensity burns, in a single-shot fashion | Procedure: Panretinal photocoagulation<br>* Panretinal photocoagulation utilizing 100ms pulse duration, moderate intensity burns, in a single-shot fashion<br>|
| Experimental: 20ms multiple-shot<br>Panretinal photocoagulation utilizing 20ms pulse duration, moderate intensity burns, in a multiple-shot fashion | Procedure: Panretinal photocoagulation<br>* Panretinal photocoagulation utilizing 20ms pulse duration, moderate intensity burns, in a multiple-shot fashion<br>|
| Experimental: 20ms multiple-shot, barely visible<br>Panretinal photocoagulation utilizing 20ms pulse duration, barely visible intensity burns, in a multiple-shot fashion | Procedure: Panretinal photocoagulation<br>* Panretinal photocoagulation utilizing 20ms pulse duration, barely visible intensity burns, in a multiple-shot fashion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of severe visual loss after 1 year | Severe visual loss is defined as visual acuity worse or equal to 5/200 in two consecutive visits (DRS/ETDRS primary outcome) | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Clinical involution of retinal new vessels | Clinical involution of retinal new vessels will be evaluated with retinography and fluorescein angiography | 1 year | 
| Nerve fiber layer thickness | Nerve fiber layer thickness will be evaluated with Spectral Domain OCT | 1 year | 
| Retinal sensitivity | Retinal sensitivity will be evaluated with Humphrey computerized perimetry and FDT (Frequency Doubling Technology) | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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diabetic retinopathy, photocoagulation, PASCAL laser