Retinal Microvascular Changes in Internal Carotid Artery Stenosis

Area of Science:

• Ophthalmology
• Neurology
• Vascular Medicine

Background:

• Internal carotid artery stenosis (ICAS) is a significant risk factor for cerebrovascular events.
• Retinal microvasculature may reflect systemic vascular health and disease.
• Optical coherence tomography angiography (OCTA) allows non-invasive visualization of retinal microvasculature.

Purpose of the Study:

• To analyze and compare retinal microvascular parameters between patients with ICAS and healthy controls.
• To investigate the impact of varying degrees of ICAS on superficial and deep capillary plexuses, radial peripapillary capillaries, and the foveal avascular zone.

Main Methods:

• Retinal microvascular parameters were assessed using OCTA in 30 patients with ICAS and 42 healthy controls.
• Patients were subclassified into mild, moderate, and severe ICAS based on Doppler ultrasonography.
• Evaluated parameters included vessel densities, foveal avascular zone area, and flow densities.

Main Results:

• Significantly reduced superficial and deep capillary plexus vessel densities were observed in the ICAS group compared to controls (p=0.000 for both).
• Radial peripapillary capillary vessel density was also decreased in patients with ICAS (p=0.004).
• No significant differences in foveal region vessel densities or foveal avascular zone area were found between groups.

Conclusions:

• Retinal microvascular alterations are a notable consequence of internal carotid artery disease.
• Even mild ICAS can induce detectable changes in the retinal microvascular network via OCTA.
• Early detection of retinal microvascular changes may offer insights into the patient's overall vascular condition.