Macular Perfusion Changes After Anti-VEGF Versus Targeted Retinal Photocoagulation in Proliferative Diabetic Retinopathy

Sponsor
Cairo University
Study ID
NCT04674254
Phase
PHASE4
Status
Completed

Conditions

Eligibility Criteria

Sex
ALL
Age
18 Years - N/A
Healthy Volunteers
Not accepted

Interventions

  • Bevacizumab Injection — DRUG
    Bevacizumab will be intravitreally injected every 4 weeks through 12 weeks then pro re nata thereafter for 12 months.
  • Targeted retinal photocoagulation — PROCEDURE
    Targeted retinal photocoagulation will be administered to nonperfused areas detected on fundus fluorescein angiography at baseline and repeated every 3 months as needed for 12 months.
  • Standard pan-retinal photocoagulation — PROCEDURE
    Standard pan-retinal photocoagulation will be applied to perfused and nonperfused areas of the retinal periphery at baseline and every 3 months as needed for 12 months.

Study Details

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus (DM), while proliferative diabetic retinopathy (PDR) is the principal cause of severe visual loss in patients with diabetes. Since 1981, Panretinal photocoagulation (PRP) has been a standard of treatment for PDR. However, PRP can be associated with adverse effects, including visual field constriction, decreased night vision, and worsening of coexisting diabetic macular edema (DME). For this reason, some authors have advocated targeted treatment with PRP. Targeted retinal laser photocoagulation (TRP) is designed to treat areas of retinal capillary non-perfusion and intermediate retinal ischemic zones in PDR that may spare better-perfused tissue from laser-induced tissue scarring. Protocol S by Diabetic Retinopathy Clinical Research Network (DRCR.net) has shown that patients that receive ranibizumab as anti-vascular endothelial growth factor (anti-VEGF) therapy with deferred PRP are non-inferior regarding improving in visual acuity to those eyes receiving standard prompt PRP therapy for the treatment of PDR. Retinal ischemia is an important factor in the progression and prognosis of diabetic retinopathy. Regarding the effect of anti-VEGF drugs on macular perfusion, several studies have shown mixed results with an increase, decrease, or no effect on perfusion in response to anti-VEGF treatment. In many of these studies, however, patients with more ischemic retinas were not included. Fluorescein angiography (FA) was the method used to assess changes in macular perfusion after anti-VEGF injections in most of the clinical trials. Despite its clinical usefulness, however, FA is known to have documented risks. Optical coherence tomography angiography (OCTA) in macular perfusion evaluation in these cases was recommended by some investigators. Several studies have proved the reliability of OCTA in detecting and quantifying macular ischemia in diabetics. The investigators aim to compare changes in the macular perfusion in patients with PDR after treatment with anti-VEGF therapy versus TRP versus Standard PRP using OCTA.

Key Dates

First listed
Dec 19, 2020
Start date
Mar 30, 2021
Status verified
Jan 2024
Primary completion
Mar 15, 2023
Completion
Mar 15, 2023

Study Design

Enrollment
43 participants (actual)
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT

Arms

  • Active Comparator: Anti-vascular endothelial growth factor agent
    Intravitreal injections of 1.25 mg/0.05 ml of Bevacizumab every 4 weeks through 12- week visit then pro re nata to complete 12 months according to Protocol S.
  • Active Comparator: Targeted retinal photocoagulation
    Targeted retinal photocoagulation guided by fundus fluorescein angiography will be administered after topical anesthesia, directed to areas of nonperfused peripheral retina plus a 1-disc area margin using the Mainster lens. Subsequent treatments if needed will be delivered at 3 monthly intervals for a minimum follow-up of 12 months. The extent of the laser applied will be determined based on areas of nonperfusion identified by fundus fluorescein angiography.
  • Active Comparator: Standard pan-retinal photocoagulation
    Standard pan-retinal photocoagulation will be performed at baseline and then every 3 months thereafter if needed, for a minimum follow-up period of 12 months. PRP will be performed at two consecutive sessions with adherence to the guidelines of the Early Treatment Diabetic Retinopathy Study Group. Following topical anesthesia, 1000 to 1200 laser spots will be applied to the retina at each session with a 532 nm frequency doubled Nd-YAG laser (VISULAS, Carl Zeiss, Germany) using a spot size of 300-500 μm. PRP will be applied in all 4 retina quadrants. The Mainster lens will be used. Retreatment will be done according to the Diabetic Retinopathy Clinical Research network protocol S classification for patients with stable, worsening, or with failure of regression of neovascularization.

Primary Outcome Measure

Change in foveal avascular zone area [ Time Frame: 0, 3, 6, 9, and 12 months ]

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