Association between Vessel Density and Visual Acuity in Patients with Diabetic Retinopathy

Background: In the non-proliferative stage, diabetic retinopathy (DR) is a retinal vascular disease. Characterised by the formation of micro aneurysms, retinal haemorrhages, exudates, venous alterations, and capillary non-perfusion. With the usage of optical coherence tomography angiography (OCTA), the purpose of this study was to determine the correlation between vessel density and best corrected visual acuity (BCVA) in DR patients.

Methods: This prospective observational research was done on 50 eyes of 35 consecutive diabetic patients who were diagnosed with mild, moderate or severe non-proliferative diabetic retinopathy (NPDR) and patients with proliferative diabetic changes (as NVD and neovascularization elsewhere (NVE)) as well as a control group consisting of 20 eyes of 10 healthy age-matched participants. Participants were divided into two groups: group A (diabetic patients): sub divided group A1: 40 eyes diagnosed with NPDR and A2: 10 eyes diagnosed with proliferative diabetic retinopathy (PDR) and group B (control group): 20 healthy eyes of age matched participants as a control group. All the eyes were subjected to fund us fluoresce in angiography (FFA) and OCTA. Comparison was made between the vascular density index (VD) in the different slaps between NPDR and PDR group, as well as correlation between the VD and BCVA.

Results: Significant positive correlation was observed between visual acuity (Log MAR) and vascular density index of superficial layer, deep layer in NPDR group and PDR group. Significant positive correlation was observed between vascular density index of superficial, deep layer and best corrected visual acuity (BCVA) (Log MAR) in NPDR group and PDR group.

Conclusions: Using OCTA enhance our awareness of the micro vascular alterations found in DR and allow assessment of disease severity.