Bevacizumab and Peripheral Retinal Changes on Wide Field Angiography in Diabetic Macular Edema

Study Overview
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Brief Summary
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Ultra-wide field fluorescein angiography can detect the response of anti VGEF therapy such as Avastin on retinal ischemia in the setting of diabetic macular edema.

Detailed Description
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The major causes of vision loss in diabetic retinopathy are diabetic macular edema (DME) characterized by thickening of the macula due to abnormal leakage of the retinal vasculature. Ischaemic changes and microvascular pathologies have long been hypothesized to play a role in the development of DME. In diabetic retinopathy, ischaemia stimulates the production of vascular endothelial growth factor (VEGF), which can lead to the breakdown of blood-retinal barriers, and may cause DME through an increase in retinal vessel permeability. DME is best evaluated by optical coherence tomography (OCT) while retinal ischemia is determined by Fluorescein angiography. With the avaiability of ultra wide field fluorescein angiography, the investigators can now accurately measure the degree of ischemia in peripheral retina. Thus, this study will provide us data on the degree of retinal ischemia in nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) cases as well as the measurable change that occurs in retinal ischemia after intra vitreal injection of bevacizumab.

Official Title
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The Effect of Bevacizumab on Peripheral Retinal Changes as Imaged by Wide -Field Fluorescein Angiography in Diabetic Macular Edema

Conditions
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Non-proliferative Diabetic Retinopathy, Proliferative Diabetic Retinopathy, Diabetic Macular Edema

Intervention / Treatment
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* Drug: Bevacizumab


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diabetic patients at age >18year with DME Scheduled for Avastin therapy Adequate media to obtain OCT and UWFA Exclusion Criteria: Macular pathology of any etiology Preexisting systemic disease causing retinal ischemia Previous laser or anti-VEGF treatment in past 3 months Previous retina surgery in past 2 months Allergy to fluorescein dye Psychiatric disorder, Alzheimer disease and Dementia or any other disorder precluding follow-up or continuation of the study.

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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Bevacizumab<br>Each study subject will recieve Intravitreal injection of 1.25mg/0.05 cc each 5 weeks for the first 3 months then PRN for six month. | Drug: Bevacizumab<br>* Intravitreal injection of 1.25mg/0.05 cc each 5 weeks for the first 3 months then PRN for six month<br>* Other names: Avastin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peripheral retinal ischemia | Change in peripheral retinal ischemia after intravitreal bevacizumab injection in non proliferative diabetic retinopathy and proliferative diabetic retinopathy. | 24 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral retinal ischemia, ultra wide field fluorescein angiography, Bevacizumab