Η επίπτωση της καρωτικής ενδαρτηρεκτομής στην οπισθοβόλβια αιμοδυναμική και στην οπτική λειτουργία

Abstract

Background: Ocular blood flow is decreased significantly in patients with mild or severe carotid stenosis, and leads to ocular ischemia, changes in haemodynamics, and eye function. Color Doppler imaging detects differences in blood flow between eyes in patients with internal carotid artery stenosis, and also assesses the improvement of retinal blood flow after carotid endarterectomy. This study examines perimetric and retrobulbar blood flow changes following carotid endarterectomy (CEA). Methods: This is a prospective interventional case series. Twenty four patients (18 males) with carotid stenosis were studied (Study Group, SG). Eight (8) healthy volunteers were also examined (Control Group, CG). Glaucoma sufferers were excluded to rule out visual field defects related with glaucoma. The retrobulbar blood flow was evaluated preoperatively and postoperativelty with CDI, using a 7.5-MHz probe. Peak systolic, end diastolic velocities and resistivity indexes (PSV, EDV, and RI respectively) were measured in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior cilliary arteries (sPCA). Visual fields were examined preoperatively with the Octopus 500perimeter (G1x program) together with CDI before and 12 months after endarterectomy. Results: Preoperative velocities at all retrobulbar vessels were significantly lower at the operated side, while increased significantly almost at the level of normal values postoperative. Preoperative perimetric parameters were significantly compromised, compared with normative data, at both eyes. Postoperatively, MD was significantly improved for both eyes, whereas improvement in other perimetric parameters examined was statistically not significant. Conclusions: Ocular blood flow is decreased significantly in patients with severe carotid stenosis, and leads to ocular ischaemia, changes in haemodynamics, eye function and visual fields. Color Doppler imaging detects differences in blood flow between eyes in patients with internal carotid artery stenosis, and also assesses the improvement of retrobulbar blood flow after carotid endarterectomy. Visual field changes following CEA imply that induced hemodynamic alterations affect visual function. Perimetric parameters may be used as additional indicators for CEA.