Microcirculatory Features of the Conjunctiva and Retina in Patients with Stable Ischemic Heart Disease and Various Patterns of Coronary Artery Involvement

Aim        A comprehensive assessment of retinal microcirculation in patients with stable ischemic heart disease (IHD) exhibiting obstructive and non-obstructive coronary artery (CA) lesions.

Materials and methods  This observational comparative study included 35 patients with stable IHD, divided into those with CA obstructive lesions (n=25) and those with ischemia with non-obstructive coronary arteries (INOCA) (n=10). A control group consisted of 30 healthy volunteers with no cardiovascular risk factors. The groups were matched for age and body mass index. All participants underwent coronary angiography or CT coronary angiography. Tissue perfusion and the amplitude-frequency spectrum of blood flow fluctuations (endothelial component) were assessed via laser Doppler flowmetry (LDF) of the bulbar conjunctiva, and optical coherence tomography angiography (OCT-A) of the macular region was performed using the SOLIX platform (Optovue, USA).

Results  Compared to the control group, patients with INOCA exhibited significantly higher vascular resistance (σ) and coefficient of variation (Kv), indicating more pronounced perfusion fluctuations. Both obstructive IHD and INOCA groups showed reduced endothelial flow amplitudes, a marker of endothelial dysfunction. OCT-A revealed that while macular vessel density remained stable, all IHD patients had increased foveal avascular zone (FAZ) area and perimeter. Specifically, the FAZ area was more significantly enlarged in obstructive IHD, whereas the FAZ perimeter was greater in INOCA (p<0.05). The left eye FAZ perimeter showed moderate diagnostic accuracy in differentiating stable IHD patients from healthy volunteers (AUC=0.632).

Conclusion         LDF of the bulbar conjunctiva effectively captures systemic vascular alterations in IHD and differentiates between obstructive and non-obstructive IHD. The integration of LDF and OCT-A provides a promising multimodal approach for the early detection of microvascular impairment, including in IHD patients.

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