Abstract
Purpose :
To identify novel OCTA vessel metrics in the macula and optic nerve head that can predict diabetic retinopathy (DR) disease progression.
Methods :
This was a prospective study of 73 patients with moderate to severe DR followed over a 12-month period between June 2017 – February 2019 as part of a Phase 2, multi-site clinical trial. All subjects were monitored with a full ophthalmic work-up including color fundus photography, SD-OCT, and OCTA of the macula and optic nerve head every 3 months. En-face OCTA full retinal projections centered at the macula were analyzed for a multiplicity of quantitative parameters including foveal avascular zone (FAZ) area and perimeter, acircularity index, vessel length, non-perfusion area, vessel density, vessel skeleton density and fractal dimension. Qualitative characteristics such as the presence of intraretinal microvascular abnormalities (IRMA), microaneurysms and capillary dropout were assessed. Optic nerve head images were segmented at the radial peripapillary capillary (RPC) layer and analyzed. Peripapillary vessel density was evaluated in four quadrants surrounding the optic disc after large vessel masking (Figure 1). Progression was defined as a ≥2-step increase in DR severity scale score (DRSS) or development of diabetic macular edema within 12-months.
Results :
Over a follow-up period of 12 months, 15 of 73 (20.5%) qualified subjects progressed. At pre-treatment baseline, larger FAZ area (b = 3.0012, p =0.037857), presence of IRMAs (b = 1.743, p =0.0167), and reduced peripapillary vessel density in the superior temporal (b = -13.531, p =0.0208) and inferior temporal (b = -16.044, p =0.0187) regions were associated with an increased risk of disease progression.
Conclusions :
This is the first study to show that reduced temporal peripapillary vessel density and FAZ area in the full retinal layer are predictors of DR progression. Our study shows the utility of OCTA as a biomarker to assess progression risk in DR.
This is a 2020 ARVO Annual Meeting abstract.