Distribution of internal carotid artery plaque locations among patients with central retinal artery occlusion in the Eagle study population.

PURPOSE: Arterial emboli in the internal carotid artery (ICA) mainly cause cerebral ischemia; only 10 % of emboli reach the retinal arteries. Computational blood flow studies suggest that plaques situated in the ICA siphon may be a source of embolism to the ophthalmic artery (OA). To validate these calculated probabilities in patients with central retinal artery occlusion (CRAO), we reanalyzed digital subtraction angiography (DSA) images from the Multicenter Study of the European Assessment Group for Lysis in the Eye (EAGLE) study, a multicenter randomized study in patients with nonarteritic CRAO.

METHODS

A reevaluation of 34 DSA studies was done from the interventional arm of the EAGLE study with regards to distribution of arterial plaques at specific ICA siphon locations and ICA stenosis. A comparison was made of plaque distribution to calculated probabilities for emboli reaching the OA from a computational fluid dynamics (CFD) model of a patient-specific ICA siphon.

RESULTS

Most of the ICA plaques near the OA's origin were located in the cavernous ICA portion (31.3%). Of these, 12.5 % had plaques in the curvature opposite the OA origin, a location carrying the highest risk for embolization into the OA (according to the CFD model 12.6-13.2 % probability of embolisation into the OA). Also, 15.6 % had plaques in the paraclinoid ICA portion distal to the OA origin.

CONCLUSIONS

There were 40.6% of the patients that had plaques in the cavernous and clinoid ICA portions presenting possible sources for embolic material generating RAO.