Characterization of Ocular Blood Flow Dysregulation Due to Carotid Artery Stenosis Using Laser Speckle Flowgraphy

Carotid stenosis is caused by a build-up of plague in carotid arteries which
carry oxygenated supply of blood to the brain. The narrowing of carotid arteries could
eventually lead to a blockage. As the eye provides a direct access to our circulation,
the ocular images offer a promising window to assess the severity of stenosis and thus
predict the likelihood of a stroke attack. This study aims to analyse and compare
longitudinal time difference in pulse waveform criterions of ocular blood flow (OBF)
between right eye as well as left eye, under common carotid artery stenosis.
Information regarding vessel condition impairment can be derived by characterizing
OBF impairment. Laser speckle flowgraphy (LSFG) is used to examine the pulse wave
parameters of OBF, such as resistive index (RI), acceleration time index (ATI), flow
acceleration index (FAI), falling rate (FR), rising rate (RR), blowout score (BOS),
blowout time (BOT), mean blur rate (MBR) and the difference in the value of MBR at
maximum and minimum point (MBRmax – MBRmin, AC) within the region of optic
nerve head (ONH) vessel, tissue and overall.