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

Purpose: The purpose of this study was to assess the effect of carotid enda rterectomy (CEA) on ocular perfusion with the measurement of the ophthalmic artery (OA) and the central retinal artery (CRA) flow velocities with colo r-flow ocular duplex scanning (ODS). Ocular hemodynamics also were examined in a subset of patients with visual symptoms in an attempt to characterize the origin of the ocular symptoms and their response to surgery. Methods: Twenty-five patients with internal carotid artery stenoses (greate r than or equal to 70%) underwent 29 CEAs. All the patients underwent ODS f or the measurement of the peak systolic velocity (PSV) in the OA and the CR A of the ipsilateral eye before and after CEA. The preoperative and postope rative now velocities were compared in all the patients and in the patients with and without visual symptoms. Results: The preoperative PSV in the OA was 21.6 +/- 2.2 cm/s and in the CR A, was 7.7 0.7 cm/s. These values were reduced as compared with normative v alues (OA, 37.8 cm/s; CRA, 10.7 cm/s). After CEA, the PSV increased signifi cantly in both vessels (postoperative OA, 38.6 +/- 2.5 cm/s, P < .0001; pos toperative CRA, 12.1 +/- 0.9 cm/s, P = .0008). Fifteen of the 29 CEAs were performed for visual symptoms. The patients with ocular symptoms had signif icantly lower preoperative PSVs in the CRA as compared with those patients without visual symptoms (CRA with ocular symptoms, 6.5 +/- 0.8 cm/s; CRA wi th no ocular symptoms, 9.4 +/- 0.9 cm/s; P = .02). The PSV in the OA was no t significantly lower in the patients with ocular symptoms. Eight patients (28%) were found to have reversed OA flow before surgery, but only three pa tients had ocular symptoms. All eight patients had normal antegrade flow in the OA after surgery. Conclusion: Severe carotid stenosis may be associated with reduced ocular p erfusion, which can be quantitatively evaluated with ODS. Reduced OA and CR A flow velocities are corrected with successful CEA. The patients with ocul ar symptoms were observed to have significant reductions in CRA flow veloci ties. 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 ev aluation of patients with atypical visual symptoms or with amaurosis fugax and no evidence of retinal emboli.