Macular Perfusion Changes After Anti-VEGF Versus Targeted Retinal Photocoagulation in Proliferative Diabetic Retinopathy
Status:
Recruiting
Trial end date:
2023-03-01
Target enrollment:
Participant gender:
Summary
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.