Characterization of one-year progression in risk phenotypes of diabetic retinopathy

Abstract

Purpose : To identify one-year progression of two nonproliferative diabetic retinopathy phenotypes B and C associated with risk of developing sight-threatening complications in type 2 diabetes (T2D).

Methods : Patients with type 2 diabetes were followed in a one-year longitudinal study. The following systemic factors were evaluated: age, sex, diabetes duration, lipidic profile, inflammatory cytokines and hemoglobin A1c (HbA1c). Ophthalmological examinations were performed at baseline, 6 months and at one-year, and included visual acuity (BCVA), color fundus photography (CFP) and optical coherence tomography (OCT and OCTA). Phenotype classification was performed based on microaneurysm turnover (MAT, on CFP) and central retinal thickness (CRT, on OCT). Only risk phenotypes were included; Phenotype B identified by low MAT (< 6) and increased CRT; and Phenotype C identified by higher MAT (≥ 6) with or without increased CRT. ETDRS grading of seven fields CFP was performed at the initial visit.

Results : To evaluate the relative risks associated with the two phenotypes, B and C, associated with increased risk of developing sight threatening complications, 1421 individuals with T2D and NPDR were recruited (81 eyes classified as phenotype B and 60 eyes classified as phenotype C), and followed for one year. Of these, 136 completed the one-year follow-up or developed DME (considering both clinically significant macular edema (CSME) and center-involved macula edema (CIME). Nineteen eyes (14%) developed either CSME (1) or CIME (18). Eleven eyes with phenotype B (14%) and 7 eyes with phenotype C (12%) developed CIME. One eye with phenotype C developed CSME. During the period of one-year, phenotype C showed a decrease in BCVA (p=0.008), in ganglion cell layer (GCL) thinning (p=0.022) and in macular vessel density in the inner ring (p=0.004), particularly in the deep retinal capillary plexus. No significant changes were detected in CRT in both phenotypes during one-year period of follow-up.

Conclusions : In one-year period of follow-up, phenotype C is the only risk phenotype that is associated with vision loss and shows disease progression at both microvascular level, represented by capillary closure, and neurodegeneration, represented by GCL thinning.

This is a 2021 ARVO Annual Meeting abstract.