Author: Ana Boned Murillo (Spain)
Co-authors: Guisela Fernandez Espinosa, Maria Dolores Diaz Barreda, Elvira Orduna Hospital, Isabel Bartolome Sesé, Javier Ascaso Puyuelo, Isabel Pinilla Lozano
To study the vascularization of the superficial capillary (SCP) and the deep capillary (DCP) retinal plexuses, as well as choriocapillaris (CC) and foveal avascular zone (FAZ) using optical coherence tomography angiography (OCTA) (DRI-Triton SS-OCT) in type 2 diabetes mellitus (DM2) patients, with moderate diabetic retinopathy (DR) without diabetic macular edema.
OCTA can detect vascular changes in DR, evaluating the SCP as well as the intermediate (ICP) and DCP, the radial peripapillary capillary network 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 detecting early microvascular changes in DM, even before they are clinically evident.
We performed a single-center cross-sectional descriptive study including 54 eyes of DM2 patients with moderate DR, and 44 age-matched healthy subjects. All participants underwent an ophthalmic examination that included refraction, axial length (AL), and OCTA using Deep Range Imaging (DRI)-Triton swept source (SS)-OCT.
Mean age was 65±15.4 and 63±13.21 years in control group and in the DM2 one, respectively. Vascular density was reduced in DM2 group achieving differences (p<0.01) between groups in central SCP (17.56±6.54 for DM2 group vs 20.71±4.62 control group), in superior SCP (44.26±4.31 for DM2 group vs 46.31% ±3.08 for control group) and nasal PCS (41.90±4.22 for DM2 group vs 44.97±3.48 for control group). FAZ was increased in the DM2 group, with differences (p<0.05) in SCP (325.41 ±164.09 µm² vs 237.56 ±95.51 µm² for control group).
There are differences between DM2 with moderate DR and the control group in retinal vascular density, being reduced in the DM2 group, especially in the SCP. The ZAF was increased in the DM2 group, and this difference was higher in the SCP