Evaluation of the Effect of Intravitreal Injections of Anti-VEGF on Macular Perfusion in Diabetic Patients Using OCTA (IMPACT)

January 21, 2020 updated by: Ayman Gehad Elnahry, Cairo University

Evaluation of the Effect of Repeated Intravitreal Injections of Anti-VEGF on Macular Perfusion in Diabetic Patients Using Optical Coherence Tomography Angiography

Anti-vascular endothelial growth factor (VEGF) drugs are the mainstay of therapy for diabetic macular edema (DME), substantially improving visual acuity for many diabetics worldwide, and proving effective for treatment of both non-proliferative and proliferative diabetic retinopathy.

Many studies such as Diabetic Retinopathy Clinical Research Network studies, RESTORE Study, and The BOLT Study have supported the use of different anti-VEGF agents in the treatment of DME with better visual outcomes using anti-VEGF injections alone or in combination with other treatments.

Several ocular complications of intravitreal anti-VEGF injections have been reported including endophthalmitis, cataract and retinal detachment. The effect of anti-VEGF drugs on macular perfusion has been inconclusive, with mixed reports of increase, decrease or no effect on perfusion in response to anti-VEGF treatment. In many of these studies, however, patients with more ischaemic retinas were not included. Retinal ischemia is an important factor in the progression and prognosis of diabetic retinopathy.

Fluorescein angiography (FA) was the method used to assess changes in macular perfusion after anti-VEGF injections in most of the studies. Despite its clinical usefulness, however, FA is known to have documented risks. Optical coherence tomography angiography (OCTA) is a new noninvasive method of acquiring high-resolution images of the retinal vasculature that can be utilized in the treatment of retinal disease without the need for dye injection. It allows the visualization of the superficial and deep retinal capillary layers separately and the construction of microvascular flow maps.

Several studies have proved the reliability of OCTA in detecting and quantifying macular ischemia in diabetics.

In this study, investigators aim to evaluate the effect of repeated intravitreal injections of different Anti-VEGF agents on the perfusion of different capillary layers in the macula of diabetic patients using OCTA.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This is a prospective interventional study to evaluate the effect of repeated intravitreal injections of Anti-VEGF on macular perfusion in diabetic patients using optical coherence tomography angiography (OCTA).

Each patient will receive a detailed ophthalmologic examination including measurement of BCVA as well as applanation tonometry, undilated and dilated slit-lamp biomicroscopic examination and indirect fundus examination.

Duration of diabetes and its control through HbA1C measurement will be recorded for each patient.

Type 1 and 2 diabetic patients found to have BCVA worse than 6/6 and clinical evidence of macular edema will undergo SD OCT and FA.

Patients with center involved macula edema detected by SD OCT will be included in the study and will undergo baseline macular OCTA.

These patients will then undergo intravitreal injections of Anti-VEGF monthly for 3 months then OCTA will be repeated to evaluate changes in macular perfusion and SD OCT will be repeated to assess retinal thickness. Patients with center involving macular edema on SD-OCT after the first 3 injections will continue to receive intravitreal Anti-VEGF injections monthly until the edema subsides or the study duration ends. These patients then undergo a final macular OCTA for perfusion evaluation and SD OCT for thickness assessment.

OCTA will be performed with an Avanti RTVue XR system (Optovue, Inc., Fremont, CA, USA). Area of FAZ and capillary density at each capillary layer will be calculated before and after interventions using the OCTA machine software and ImageJ software.

All statistical analyses will be done using IBM SPSS v20.0 statistical software (IBM Corporation, NY, USA). Descriptive statistics will be calculated, and the data will be summarized as mean ± SD for numerical data, and as frequencies and percentages for categorical data.

Study Type

Interventional

Enrollment (Actual)

31

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Egypt
      • Cairo, Egypt
        • Cairo University faculty of medicine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Patients ≥ 18 years old
  2. Type 1 or 2 diabetes mellitus
  3. Decreased BCVA due to diabetic macular edema
  4. Center involvement by the edema on spectral domain optical coherence tomography (SD OCT)
  5. Any stage of diabetic retinopathy

Exclusion Criteria:

  1. Ocular conditions that may affect macular perfusion (e.g. retinal vascular diseases, uveitis, vasculitis etc.)
  2. History of vitreoretinal surgeries (excluding intravitreal injections)
  3. Any previous treatment for diabetic macular edema
  4. Presence of epiretinal membrane involving the macula or vitreomacular traction
  5. Media opacity preventing good image quality
  6. Uncontrolled glaucoma
  7. Thromboembolic events within 6 months

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Bevacizumab group
Monthly intravitreal injection of 2.5 mg of Bevacizumab for at least 3 consecutive months. This is followed by treat and extend regimen after resolution of macular edema.
Drug: Bevacizumab
Repeated intravitreal injections of Bevacizumab monthly
Other Names:
  • Avastin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
FAZ Area Change
Time Frame: At baseline and after 3-6 consecutive monthly injections.
Effect of repeated intravitreal Anti-VEGF injections on Foveal Avascular Zone (FAZ) area measured using the freehand tool of ImageJ
At baseline and after 3-6 consecutive monthly injections.
Macular Capillary Density Change at Full Retinal Thickness
Time Frame: At baseline and after 3-6 consecutive monthly injections.
Effect of repeated intravitreal Anti-VEGF injections on macular capillary density using the change in the skeletonized vascular density and fractal dimension measured by ImageJ
At baseline and after 3-6 consecutive monthly injections.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
BCVA Change
Time Frame: At baseline and after 3-6 consecutive monthly injections.
Correlation of BCVA change with degree of capillary non-perfusion before and after injections
At baseline and after 3-6 consecutive monthly injections.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Cairo University

Investigators

  • Principal Investigator: Ayman GA Elnahry, MSc, Cairo University
  • Study Director: Khaled E El Rakhawy, PhD, Cairo University
  • Study Director: Karim A Raafat, PhD, Cairo University
  • Study Chair: Ahmed AA Abdel Kader, PhD, Cairo University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 23, 2017

Primary Completion (Actual)

December 24, 2018

Study Completion (Actual)

December 24, 2018

Study Registration Dates

First Submitted

August 6, 2017

First Submitted That Met QC Criteria

August 8, 2017

First Posted (Actual)

August 11, 2017

Study Record Updates

Last Update Posted (Actual)

January 30, 2020

Last Update Submitted That Met QC Criteria

January 21, 2020

Last Verified

January 1, 2020

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • N-79-2017

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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