Intravitreal Bevacizumab vs Laser vs Combination of Bevacizumab and Modified Laser in PDR

Study Overview
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Brief Summary
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In this randomized 3-armed clinical trial, 105 eyes with PDR will be included and divided randomly into 3 groups: IVB group (35 eyes) that receive 4 monthly IVB injections and then rescue IVB, PRP group (35 eyes) that undergo full PRP in 2 or 3 sessions and then rescue IVB, and combination group (35 eyes) that receive 2 bimonthly IVB injections and a modified laser (1 session anterior to the equator) and then rescue IVB or laser. Diabetic macular edema (DME) will be treated independently in all groups by IVB. Primary outcome will be the number and activity of neovascularizations at 4,8 and 12 months and secondary measures will be changes in best corrected visual acuity (BCVA) and central macular thickness (CMT), and number of examinations and injection.

Official Title
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Combination Therapy for PDR

Conditions
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Proliferative Diabetic Retinopathy

Intervention / Treatment
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* Drug: receive 4 monthly IVB injections and then rescue IVB
* Drug: PRP group
* Drug: IVB injections and a modified laser


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Presence of PDR with the indication of full PRP according the intend of investigator Best corrected visual acuity of 20/320 or better Media clarity, pupillary dilation and patient's cooperation sufficient for full PRP, wide-field FAG and OCT Exclusion Criteria: History of prior PRP with more than 100 burns outside the posterior pole Tractional retinal detachment involving the macula Evidence of neoplasia of angle on examination Macular edema due to a cause other than DME Any ocular condition which may change visual acuity during the study Substantial cataract which has declined the vision by 3 lines or more History of intravitreal injection of anti-VEGF agent in past 2 months History of any use of corticosteroid during past 4 months History of major intra-ocular surgery except cataract surgery History of YAG laser capsulotomy during past 2 months Aphakia and uncontrolled glaucoma according to investigator judgment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: intravitreal bevacizumab injections and then rescue<br> | Drug: receive 4 monthly IVB injections and then rescue IVB<br>* IVB group that receive 4 monthly IVB injections and then rescue IVB<br>|
| Active Comparator: PRP group<br> | Drug: PRP group<br>* PRP group that undergo full PRP in 2 or 3 sessions and then rescue IVB<br>|
| Active Comparator: IVB injections and a modified laser<br> | Drug: IVB injections and a modified laser<br>* Combination group that receive 2 bimonthly IVB injections and a modified laser (1 session anterior to the equator) and then rescue IVB or laser<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Extent of neovascular tissues in disc-diameter measured by investigator according to the wide-field FAG | Number of neovascular tissue counted by investigator according to FAG | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best corrected visual acuity based on Snellen chart |  | 12 months | 
| Central retinal thickness according to macular OCT |  | 12 months |