Assessment of ocular perfusion after carotid endarterectomy with color-flow duplex scanning

Abstract

Severe carotid stenosis may be associated with reduced ocular perfusion, which can be quantitatively evaluated with ODS. Reduced OA and CRA flow velocities are corrected with successful CEA. The patients with ocular symptoms were observed to have significant reductions in CRA flow velocities. Reversed flow in the OA was not a marker for ocular symptoms in this study. ODS can identify global ocular ischemia and may be helpful in the evaluation of patients with atypical visual symptoms or with amaurosis fugax and no evidence of retinal emboli.

Retinal embolization after carotid endarterectomy and stenting for carotid artery stenosis

“…In addition, an anastomosis of the external carotid circulation to the ICA (for example, the orbital branch of the middle meningeal artery to the ophthalmic artery) may form with a carotid stenosis [6]. Approximately 28-35% of preoperative CEA patients exhibit reversed flow in the ophthalmic artery before surgery [7][8][9]. Transient blindness and amaurosis fugax have been reported in patients with a totally occluded ipsilateral ICA, clearly establishing the collateral pathway as a mechanism for retinal embolization [10].…”

Improvement in Cerebral and Ocular Hemodynamics Early after Carotid Endarterectomy in Patients of Severe Carotid Artery Stenosis with or without Contralateral Carotid Occlusion

“…The OA is located downstream of the ICA, and the inflow artery for the OA is the ICA. Severe CS was associated with a marked reduction in OA and CRA flow velocities, which were corrected with successful CEA [15]. Kawaguchi et al demonstrated that the BFV in OA increased from 9 ± 5 cm/s to 21 ± 5 cm/s one week after CEA [16].…”

“…Rutgers et al indicated that the proportion of reversed OA flow ipsilateral to severe CS decreased significantly from 42% before to 5% at six months after CEA [12]. Cohn Jr. et al reported that eight patients with preoperative OA flow reversal had a return of normal OA flow within one month following CEA [15]. Zbornikova and Skoglund demonstrated that a change in the flow direction from being retrograde to antegrade was noted in 9/10 patients (90%) within forty-eight hours after CEA [17].…”

“…The reverse OA flow from ECA supplies the ipsilateral brain in response to reduced inflow pressure in the OA [14]. Previous studies reported that CEA resulted in significantly increased flow in the OA and that it corrected reversed flow in the OA in patients of severe CS [15–17]. Central retinal artery (CRA) and short posterior ciliary artery (SPCA) are two major terminal branches of OA, supplying all the structures in the orbit.…”

Reply: Transient retinal artery occlusion during phacoemulsification cataract surgery

“…High diastolic systemic arterial pressures may be protective, maintaining OPP throughout the cardiac cycle despite peri-operative elevations in IOP. Conversely, carotid artery stenosis is associated with reduced ipsilateral OPP 6 and may risk TRAO in the context of relatively minor fluctuations in IOP.…”