Retinal microcirculation as a window to coronary artery disease

Area of Science:

• Ophthalmology and Cardiology
• Biomarkers and Diagnostic Imaging
• Vascular Biology

Background:

• Coronary artery disease (CAD) encompasses epicardial stenosis and ischemia due to microvascular dysfunction.
• Current coronary artery disease screening methods are invasive and costly.
• Retinal imaging offers accessible biomarkers reflecting both epicardial atherosclerosis and coronary microvascular dysfunction.

Purpose of the Study:

• To summarize the links between retinal measures and coronary anatomy, physiology, and clinical phenotypes.
• To inform risk assessment strategies for coronary artery disease.
• To explore the potential of retinal imaging in differentiating CAD endotypes.

Main Methods:

• Narrative synthesis of studies.
• Linking retinal structure and perfusion metrics (fundus, OCT/OCTA, FAZ, choroidal indices) with coronary angiography, functional ischemia indices (CFR, IMR, MFR), and clinical phenotypes (obstructive CAD, INOCA, slow coronary flow).

Main Results:

• Retinal microvascular alterations (narrower arterioles, wider venules, lower arteriovenous ratio) predict CAD, MI, stroke, and mortality.
• OCT angiography shows reduced vessel density and enlarged FAZ correlating with CAD severity and risk profiles.
• Retinal findings in coronary microvascular dysfunction (CMD)/Ischemia with Non-Obstructive Coronary Arteries (INOCA) show generalized microvascular dysfunction, including sex-specific differences and links to slow coronary flow.

Conclusions:

• Retinal imaging provides accessible biomarkers for systemic vascular alterations in CAD.
• Retinal imaging may assist in risk stratification and endotype differentiation for CAD.
• Clinical translation requires standardized studies, AI analytics, and integration with quantitative coronary physiology to overcome current limitations.