Author: Luisa Ribeiro (Portugal)
Co-authors: Rita Coimbra, Torcato Santos, Maria H. Madeira, Ana Rita Santos, Conceição Lobo, José Cunha-Vaz
Phenotypes of diabetic retinopathy (DR), particularly B and C, have been shown previously to be associated with risk of progression and development of sight-threatening complications (macular edema and proliferative retinopathy). In this study we aim characterized systemically and locally, the one-year progression of these non-proliferative diabetic retinopathy phenotypes, B and C, associated with risk of developing sight-threatening complications in type 2 diabetes (T2D).
Clinical Trial Center – AIBILI, Coimbra - Portugal
141 individuals with T2D and NPDR (ETDRS 20 to 47), were followed in a 1-year longitudinal study. Demographic and systemic factors were evaluated: age, sex, diabetes duration, lipidic profile, blood pressure and hemoglobin A1c (HbA1c) levels. Ophthalmological examinations, performed at baseline and one-year, included visual acuity (BCVA), color fundus photography (CFP) and optical coherence tomography (OCT and OCTA). ETDRS grading of seven fields CFP was performed at the initial visit. 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 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. Retinal vessel closure was assessed OCTA metrics in Superior Capillary Plexus (SCP), Deep Capillary Plexus (DCP) and Full Retina. Neurodegeneration accessed by OCT segmentation and quantification of Ganglion Cell Layer + Inner Plexiform Layer (GCL+IPL) thickness
To evaluate the relative risks associated with the two phenotypes, B and C, associated with increased risk of developing sight threatening complications, 141 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, 135 completed the one-year follow-up or developed DME (considering both clinically significant macular edema (CSME) and center-involved macula edema (CIME). During the period of one-year, and at systemic level, the study population showed significant lower levels of LDL cholesterol and increased HDL (p<0.001), and higher systolic pressure (p=0.038). Locally, ophthalmological evaluations revealed a decreased in vessel density in the DCP (p<0.001), increased BCVA (logmar scale) (p=0.007) and decrease in GCL+IPL thickness (p<0.001) and MAT (p<0.001). When comparing phenotypes B and C, the main significant differences observed were in systolic blood pressure (p=0.024), GCL+IPL thickness (p=0.016) and, as by definition, MAT (p<0.001). A spearman correlation revealed moderate associations between vessel density, GCL+IPL Thickness and BCVA for phenotype C, particularly at 12-month visit.
In one-year period of follow-up, only phenotype C show disease progression in neurogenerative changes (GCL+IPL thinning), which correlate with decreases in vessel density, GCL+IPL thickness and visual acuity, particularly apparent in the 12 months visit.
José Cunha-Vaz is consultant: Carl Zeiss Meditec, Ciana Therapeutics, Alimera Sciences, Boehringer Ingelheim, Allergan, Bayer, Gene Signal, Novartis, Pfizer, Oxular, Roche, Sanofi, Vifor Pharma, Adverum Biotechnologies.