Author: María Dolores Díaz Barreda (Spain)
Co-authors: María Sopeña Pinilla, Ana Boned Murillo, Elvira Orduna Hospital, Isabel Bartolomé Sesé, Ismael Bakkali El Bakkali, Isabel Pinilla Lozano
To study anatomical and vascular changes in the superficial capillary (SCP) and deep capillary (DCP) plexuses in the retina, as well as changes in the choriocapillaris (CC) and foveal avascular zone (FAZ) using optical coherence tomography angiography (OCTA) (DRI-Triton SS-OCT) in type 1 diabetic (DM1) patients without diabetic retinopathy (DR).
OCTA can detect vascular changes in DR, evaluating SCP and DCP and the CC. Vascular density, perfusion areas and FAZ morphology and area are the most investigated OCTA quantitative parameters to evaluate severity and prediction of DR, and it can also be used as a treatment marker. In this way, the early diagnosis of DR can be carried out with OCTA, since it allows to detect early microvascular changes in DM, even before they are clinically evident.
We performed a single-center cross-sectional descriptive study including 40 eyes of well-controlled DM1 patients who had been diagnosed at least 10 years prior, and 72 eyes of 72 healthy subjects. All participants underwent a full ophthalmic examination including OCTA using Deep Range Imaging (DRI)-Triton swept source (SS)-OCT.
Mean age was 41.70±11.48 and 42.78±13.70 years in DM1 group and in the control group respectively. There were no differences in visual acuity (VA), spherical equivalent (SE), axial length (AL) nor intraocular pressure (IOP). Statistical differences were found in all areas of the SCP, with lower values in DM1 patients. There were differences in all quadrants except the central zone in the DCP. In the CC there were only significant blood flow changes in the central area. We did not find significant differences in the FAZ in neither of the plexuses, but the horizontal FAZ SCP diameter was found significantly different. The anatomical evaluation frequently showed abnormalities such as microaneurysms in both plexuses, FAZ modifications and areas with lack of blood perfusion.
Diabetic patients without DR present microvascular abnormalities with lack of retinal and CC blood perfusion, as well as anatomical changes in retinal blood vessels.