Evaluation of the Effect of Intravitreal Injections of Anti-VEGF on Macular Perfusion in Diabetic Patients Using OCTA
Condition: Diabetic Macular Edema; Ischemic Maculopathy
MeSH terms: Macular Edema; Macular Degeneration
Intervention: Bevacizumab
Intervention description: Repeated intravitreal injections of Bevacizumab monthly
Intervention MeSH terms: Bevacizumab
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 31.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Anti-VEGF safety; Ischemic Maculopathy; Diabetic Macular Edema; OCTA

Summary:

      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.
    

Eligibility criteria:

        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