Abstract: Objective  To assess the risk of coronary atherosclerotic heart disease (CAD)  in patients with dyslipidemia based on the retinal vascular change via optical coherence tomography angiography (OCTA). Methods  A cross-sectional analysis was conducted on 261 dyslipidemia patients who were admitted to the Department of Geriatrics  between December 2022 and March 2024. Subjects were stratified into CAD and non-CAD groups. OCTA imaging was used to quantify retinal vessel density (VD) in the optic disc, retinal nerve fiber layer (RNFL) thickness, macular VD-including that of superficial capillary plexus (SCP) and deep capillary plexuses (DCP), with separate assessments in the parafoveal and perifoveal regions. Additional quantified parameters included macular retinal thickness, foveal avascular zone (FAZ) area, FAZ perimeter, and VD within the 300 μm annular region surrounding the FAZ (FD). Multivariable regression analysis was applied to evaluate the association between CAD and various OCTA measurements.  Group comparisons of OCTA parameters were performed, followed by receiver operating characteristic (ROC) curve analysis to determine the discriminative power of SCP perifoveal VD and FD in identifying CAD in dyslipidemia patients. Results  RNFL thickness and VD of both total and small vessels in the optic disc region did not differ significantly between CAD and non-CAD groups. In the macular area, a reduction in SCP parafovea and perifovea VD was detected in CAD patients. However, statistical significance was reached only for the SCP perifoveal VD. No meaningful intergroup differences emerged in DCP VD or retinal thickness. In the FAZ, the FD was lower in the CAD group, while the differences in FAZ area, perimeter, and thickness remained insignificant between groups. Further multivariate regression analysis revealed that CAD was negatively associated with both the SCP perifoveal VD and FD, with β values ranging from －1.465 to －1.908. Comparative OCTA assessment informed ROC curve construction, which confirmed the assessment value of SCP perifovea VD and FD in distinguishing CAD in dyslipidemic patients. Based on the Youden index, optimal threshold values were identified as 47.275% for SCP perifoveal VD and 53.09% for FD. Given that both indices reflect superficial retinal vascular density, they were integrated into a composite parameter. ROC analysis revealed that this composite metric yielded superior area under the curve (AUC) performance compared to either individual component. The Youden index identified 96.265% as the optimal threshold for this composite metric. Conclusions  Dyslipidemic patients with CAD exhibited reduced SCP VD compared to those without CAD. Retinal VD measurements offer promising utility as a novel indicator for CAD risk assessment in dyslipidemia populations.

Key words: dyslipidemia, coronary atherosclerotic heart disease (CAD), risk, retinal vessels, optical coherence tomography angiography (OCTA), vessel density