Abstract
Purpose :
To characterize the two-year occurrence of macular edema of different diabetic retinopathy phenotypes in type 2 diabetes (T2D) focusing in changes in central retinal thickness (CRT).
Methods :
A prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted with 3 visits (baseline, 6-months and two-year). Demographic and systemic data included age, sex, diabetes duration, lipidic profile and hemoglobin A1c (HbA1c). Ophthalmological examinations included visual acuity, color fundus photography (CFP) and optical coherence tomography (OCT and OCTA), identified the presence of nonproliferative diabetic retinopathy. Phenotype classification was performed, at 6-month visit, based on microaneurysm turnover (MAT, on CFP) and CRT (on OCT). Only risk phenotypes B (MAT<6 and increased CRT) and Phenotype C (MAT≥6 with or without increased CRT) were included. ETDRS grading was performed at the baseline and last visits based on 7-fields CFP. OCT data was analyzed with OCT-Leakage, a novel technique for noninvasive assessment of abnormal accumulation of fluids in the retina through low optical reflectivity ratios (LOR).
Results :
Of the 133 T2D individuals included in the study, 81 eyes (60%) 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.
Patients that developed CIME showed an increase in CRT with time when compared to patients that did not (ß=10.318, p<0.001). This difference remains statistically significant when controlling for age, sex, diabetes duration and HbA1c.
Changes in time for CRT, over the two-year period of follow-up, are positively associated with longitudinal changes in LOR ratios (ß=53.113, p<0.001) and with longitudinal changes in vessel density (increase) in the deep capillary plexus (ß=0.811, p<0.001) and superficial capillary plexus (ß=1.516, p<0.002). Patients with different ETDRS levels have similar alterations across visits for CRT, as well as for both phenotypes, B and C.
Conclusions :
In the two-year period of follow-up CRT changes followed similar response patterns for both phenotypes and different ETDRS levels. CRT changes showed a clear association with the development of CIME.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.