Abstract
Purpose :
To characterize the two-year progression of capillary closure in different diabetic retinopathy (DR) risk phenotypes in type 2 diabetes (T2D).
Methods :
A prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted with 4 visits (baseline, 6-months, one-year and two-year). Demographic and systemic data included age, sex, diabetes duration, lipidic profile and hemoglobin A1c (HbA1c). Ophthalmological examinations including visual acuity (BCVA), color fundus photography (CFP) and optical coherence tomography (OCT and OCTA) identified nonproliferative diabetic retinopathy (NPDR). Phenotype classification was performed, at 6-month visit, based on microaneurysm turnover (MAT, on CFP) and central retinal thickness (CRT, on OCT). Only risk phenotypes B (MAT<6 and increased CRT) and C (MAT≥6 with or without increased CRT) were included. ETDRS grading was performed at the baseline and last visit based on 7-fields CFP.
Results :
133 T2D individuals were included in the study, 81 (60%) eyes classified as phenotype B and 52 (40%) eyes as phenotype C. Of these, 127 completed the two-year follow-up with 24 (19%) developing central-involved macular edema (CIME) and 2 (1.6%) clinically significant macular edema (CSME).
At baseline, eyes with phenotype C showed more capillary closure in the superficial capillary plexus (SCP), deep capillary plexus (DCP) and full retina (FR), p<0,001) and increased FAZ area (p<0,001), indicating more advanced ischemic disease. During the two-year follow-up period, the decrease in skeletonized vessel density indicating capillary closure, occurred mainly in the DCP in both phenotypes. Positive associations with the increased capillary closure were identified with GCL+IPL thinning (representing neurodegeneration) and decreased BCVA.
Conclusions :
Significant progression in capillary closure was identified by a decrease in vessel density in the deep capillary plexus occurring in both phenotypes and in the different ETDRS levels. Eyes developing CIME had less decrease in vessel density of the SCP at baseline.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.