Multimodal retinal imaging in patients with diabetes mellitus and association with cerebrovascular disease

Introduction: The aim of the study is to evaluate the association between optical coherence tomography angiography (OCT-A) metrics of the macula and ultrawide field imaging and cerebrovascular disease in patients with diabetes mellitus (DM) with different stages of diabetic retinopathy (DR)Methods: 516 eyes of 258 DM patients were enrolled in two centers (Milan and Belfast). Ultrawide field color fundus photos (CFP) were obtained with Optos California (Optos, PLC) and graded for both DR severity and predominantly peripheral lesions (PPL) presence (>50% of CFP lesions) by two independent graders. OCT-A (3x3 mm), available in 252 eyes of 136 patients, was used to determine perimeter, area and circularity index of the foveal avascular zone (FAZ) and vessel density (VD); perfusion density (PD); fractal dimension (FD) on superficial (SCP), intermediate (ICP) and deep (DCP) capillary plexuses; flow voids (FV) in the choriocapillaris (CC).Results: Out of 516 eyes, 108 eyes (20.9%) did not have DR, and 6 eyes were not gradable. The remaining 402 eyes were: 10.3% (53) mild nonproliferative DR (NPDR), 38.2% (197) moderate NPDR, 11.8% (61) severe NPDR, 17.6% (91) proliferative DR (PDR). A worse DR stage was associated with a history of stroke (p=0.044). Logistic regression analysis after taking into account sex and type of DM, and age, DM duration and OCT-A variables, found that PD and VD on ICP were significantly associated with presence of stroke and DR severity. Conclusion: OCT-A metrics show an association with the presence of cerebrovascular complications, providing potentially useful parameters to estimate vascular risk in patients with DM.