Pattern Scanning Laser Pan-retinal Photocoagulation in Proliferative Diabetic Retinopathy

Study Overview
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Brief Summary
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A randomized study to assess the safety and efficacy of single-session pan-retinal photocoagulation (PRP) using Pattern Scan Laser (PASCAL) in proliferative diabetic retinopathy (PDR) - 1,700 shots vs 2,500 shots

Official Title
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Single-session Pattern Scanning Laser Pan-retinal Photocoagulation in Proliferative Diabetic Retinopathy - a Randomized Study

Conditions
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Diabetic Retinopathy, Lasers, Treatment Outcome

Intervention / Treatment
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* Device: Pan-retinal photocoagulation using pattern scanning laser


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All treatment-naïve patients with proliferative diabetic retinopathy (PDR) who attended our ophthalmic clinic from 1st December 2012 to 30th November Exclusion Criteria: significant media opacity affecting laser uptake (e.g. corneal opacity, mature cataract, dense vitreous haemorrhage) any pre-existing ocular disorders resulting in visual impairment (e.g. retinal degenerations, maculopathies, primary glaucoma and other optic neuropathies) those who received previous retinal laser treatment, intravitreal injections or intraocular surgeries clinically significant macular oedema on clinical examination.

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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1,700<br>Patients receive 1,700 (+/- 5%) laser shots in a single session of pan-retinal photocoagulation using pattern scanning laser | Device: Pan-retinal photocoagulation using pattern scanning laser<br>* Patients receive the designated number of laser shots of pan-retinal photocoagulation with pattern scanning laser in a single session<br>|
| Active Comparator: 2,500<br>Patients receive 2,500 (+/- 5%) laser shots in a single session of pan-retinal photocoagulation using pattern scanning laser | Device: Pan-retinal photocoagulation using pattern scanning laser<br>* Patients receive the designated number of laser shots of pan-retinal photocoagulation with pattern scanning laser in a single session<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regression of neovascularization | Fluorescein angiogram assessment by independent observer | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Activity of neovascularization | Descriptive analysis of fundus fluorescein angiogram by independent observer into 4 categories: no leakage, reduced leakage, same leakage, increased leakage | 3 months | 
| Best corrected visual acuity |  | 1 week, 1 month, 3 months, 6 months | 
| Complications | choroidal detachment, exudative retinal detachment, retinal breaks | 1 week, 1 month, 3 months, 6 months | 
| Central foveal thickness | Measured by spectral domain optical coherence tomography (Heidelberg Spectralis) | 1 week | 
| Retreatment rate | Patients requiring retreatment with pan-retinal photocoagulation | 6 months |