Retinal artery occlusion during carotid artery stenting with distal embolic protection device

Bilateral retinal artery occlusions with carotid artery occlusions-ocular and cerebral hemodynamic changes

Purpose

To introduce a case of bilateral retinal artery occlusions with carotid occlusions to achieve a fuller understanding of hemodynamic flow changes and the origin of emboli.

Observations

A 58-year-old male presented with binocular vision loss. Fundus examination revealed bilateral retinal whitening with multiple emboli. Cherry red spot was surrounded and shaped by white edematous ischemic retina. FAG showed retinal refilling but not to the macula and choroidal background. Carotid arteriography and color Doppler images demonstrated bilateral carotid occlusions. CT angiography showed compensatory flows perfused from vertebral arteries for the brain. Orbital color Doppler images revealed bilateral reversed ophthalmic flows indicating another compensatory flow arising from external carotid/ophthalmic collaterals to both eyes.

Conclusions and Importance

Reversed ophthalmic flow indicates the presence of external carotid/ophthalmic collaterals as the source of ocular blood supply and the origin of emboli. In this case, all the embolic, hemodynamic, and serotonin mechanisms may be responsible for the pathogenesis. RAO with multiple emboli is an important sign warning critical flow changes of carotid occlusions.

Retinal arterial occlusion with multiple retinal emboli and carotid artery occlusion disease. Haemodynamic changes and pathways of embolism

Objective

To introduce a special subgroup, retinal artery occlusion (RAO) with multiple emboli, which is highly associated with ipsilateral carotid artery occlusion disease (CAOD).

Methods and analysis

This is a cohort study. Cases of RAO with multiple retinal emboli were consecutively enrolled. All patients underwent at least one of the carotid/cerebral evaluations: carotid arteriography, orbital/carotid colour Doppler ultrasonography and CT angiography to demonstrate haemodynamic changes and to discuss possible mechanisms and pathways of the emboli.

Results

Among 208 RAO eyes, 12 eyes (5.7%) in 11 patients had multiple emboli were recruited in this study. Eleven eyes (91.6%) had ipsilateral carotid plaques and atherosclerosis with high-grade stenosis; among them, five were total carotid occlusion. Haemodynamic changes were found in nine patients with RAO (81.8%) with carotid stenosis 60% or greater. Most compensatory intracranial circulations were re-established via the circle of Willi with antegrade ophthalmic flows, but the direction of ophthalmic flow reversed in three eyes indicating the recruitment of external collaterals. Two cases underwent carotid stent successfully.

Conclusion

RAOs with multiple emboli are rare but highly associated with severe CAOD with haemodynamic flow changes, warning critical condition in carotid/cerebral circulations. Either direct embolism from the carotid or cardiac lesions or indirect embolism via the collateral pathways is the mechanism of pathogenesis. Immediate action should start to manage these patients to prevent further deterioration.