Abstract
Purpose :
To characterize the two-year progression of neurodegeneration in different diabetic retinopathy (DR) risk phenotypes in type 2 diabetes.
Methods :
A prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted with 3 visits (baseline, 6-months and one-year). Demographic and systemic data included age, sex, diabetes duration, lipidic profile and hemoglobin A1c (HbA1c). Ophthalmological examinations included visual acuity (BCVA), color fundus photography (CFP) and optical coherence tomography (OCT and OCTA). 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 :
Of the 133 T2D individuals included in the study, 81 (60%) eyes were 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).
Neurodegeneration represented by thinning of the GCL+IPL was present in both phenotypes showing no differences between these phenotypes. Furthermore, GCL+IPL thickness decreased with time (average of -0.605 µm/year; p=0.010). This decrease remained statistically significant (ß=0.624, p=0.006) when controlling for age, sex, diabetes duration and HbA1c. Changes in time for GCL+IPL thickness are also associated with longitudinal changes in FAZ area, FAZ perimeter and deep capillary plexus vessel density particularly in phenotype C. No correlation was found between the presence of increased neurodegeneration and the development of CIME.
Conclusions :
In the two-year period of follow-up both phenotypes B and C showed similar progression in retinal neurodegenerative changes. The neurodegeneration is associated with microvascular related variables indicative of capillary closure. There is no association between the progression in neurodegeneration and development of CIME.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.