The retina as a window to the coronary arteries: retinal ischemic perivascular lesions (RIPL) identify coronary angiographic complexity in acute coronary syndrome

Background Retinal ischemic perivascular lesions (RIPL) are chronic macular signatures visible on spectral-domain optical coherence tomography (SD-OCT) and are considered sequelae of ischemia in the deep retinal capillary plexus within the spectrum of paracentral acute middle maculopathy. Recent studies suggest that RIPL may reflect systemic vascular vulnerability and have been associated with cardiovascular diseases, including myocardial infarction. However, their relationship with coronary anatomical complexity in acute coronary syndrome (ACS) remains poorly explored. Objective To evaluate the association between the presence of RIPL detected by SD-OCT and the severity of coronary artery disease assessed by coronary angiography in patients presenting with ACS. Methods This observational study included consecutive patients admitted for ACS who underwent coronary angiography, with or without percutaneous coronary intervention, followed by systematic retinal SD-OCT imaging. To minimize confounding related to diabetic microangiopathy, patients with diabetes were excluded. RIPL were defined according to established OCT criteria as focal perivenular thinning of the inner nuclear layer. Coronary disease severity was assessed using the SYNTAX and lesion burden, defined by the total number of coronary lesions and the number of significant stenoses. Associations between RIPL presence and angiographic parameters were evaluated using non-parametric tests, Spearman correlations and multivariable regression models adjusted for major cardiovascular risk factors. Results Among 150 non-diabetic patients presenting with ACS, RIPL were detected in 27 patients (18%). Patients with RIPL exhibited significantly higher coronary anatomical complexity compared with those without RIPL. The median SYNTAX was 25 [22–30] in the RIPL group versus 14 [8–20] in the non-RIPL group (p < 0.001). RIPL presence was significantly correlated with the SYNTAX (ρ ≈ 0.50; p < 0.001). High coronary complexity (SYNTAX ≥22) was significantly more frequent in RIPL-positive patients (≈70% vs ≈25%; adjusted OR ≈5–6; p < 0.001). Lesion burden was also higher in patients with RIPL, with a greater number of significant coronary stenoses (4 [3–5] vs 2 [1–3]; p < 0.001). Importantly, RIPL remained independently associated with high coronary complexity after multivariable adjustment for age, sex, smoking and dyslipidaemia. Conclusion In non-diabetic patients presenting with ACS, the presence of RIPL detected by retinal OCT is associated with greater coronary anatomical complexity and higher lesion burden. These findings suggest that retinal micro-ischemic footprints may reflect systemic atherosclerosis and could represent a simple, non-invasive biomarker for coronary risk stratification. These findings support the concept of the retina as a non-invasive window to systemic atherosclerotic disease. Larger prospective studies are needed to further evaluate their prognostic value.