A full-width half-maximum method to assess retinal vascular structural changes in patients with ischemic heart disease and microvascular angina

Chest pain patients without obstructive ischemic heart disease (IHD) have increased attention in the clinical practice as carrying higher cardiovascular (CV) risk and impaired life quality. Retinal vasculature is a novel but reliable risk factor of atherosclerosis and systemic vascular diseases. However, the association of retinal blood vessels and unobstructed IHD, as known as microvascular angina (MA) is poorly understood. This study compared retinal vascular structures of obstructive IHD and MA using spectral domain optical coherence tomography (SD-OCT) and full-width half-maximum (FWHM) methods to provide new risk predictive evidence of MA. Fundus vessels of 120 IHD patients, including 91epicardial IHD and 29 MA patients, and 66 control subjects were evaluated. Significant differences in the retinal arterial lumen diameter (RALD), retinal arterial outer diameter (RAOD), and arteriovenous ratio (AVR) have been found (P < 0.05). The severity of IHD was negatively correlated with diameters of RAOD, RALD and AVR (P < 0.05). In conclusion, there were significant differences in the retinal vascular structure between IHD patients and patients with MA. Thus, assessment of retinal vascular structure is suggested to evaluate CV risk of IHD patients, despite having no obstructive IHD.