Abstract
Purpose: :
It is commonly accepted that internal carotid artery stenosis is one of the factors that influences arm–retina time in fluorescein angiography. However, there is inadequate data to indicate what level of delayed filling, if any, should prompt the ophthalmologist to recommend a vascular work up. This study examines the correlation between the arm–retina time obtained from patients undergoing fluorescein angiography with significant carotid artery stenosis.
Methods: :
In this retrospective study, we reviewed the charts of patients that underwent fluorescein angiography (FA) at the Yale Eye Center from 1998 to 2004. Patients with slow injection times or injection sites other than the antecubital fossa were excluded. Further identifying those patients who underwent carotid ultrasound (CUS) before or up to 1.5 years after their FA, we examined the arm–retina time (ART), defined as the length of time between the initiation of injection to the first indication of fluorescence within the retinal arteries. Clinically significant stenosis was defined as greater than or equal to 50% by CUS, while severe stenosis was defined as greater than or equal to 70%.
Results: :
87 patients met the inclusion criteria, with a mean ART of 18.66 (95% CI of 17.64 to 19.68). There was no correlation between age and ART (r = –0.01, p=0.96), nor any significant difference in age between those with and without stenosis (74.94 vs. 72.50, p=0.22). There was also no significant difference in ART between diabetics vs. non–diabetics (18.61 vs. 18.70, p=0.93). Patients without stenosis had a slightly longer average ART than those with it, although it was not significant (19.14 vs. 17.98, p=0.27). There was no significant difference between those with severe stenosis and those without it (18.25 vs. 18.78, p=0.66). Of the 14 patients who had specifically received CUS for delayed ART, two had stenosis (14.3%) and one had severe stenosis (7.1%). Three of six patients (50%) sent for CUS on the basis of asymmetric diabetic retinopathy had stenosis and two of six patients (33.3%) had severe stenosis. Population–based epidemiological studies have found the rate of stenosis in similar demographic groups to be anywhere from 4% to 28%.
Conclusions: :
Our results show no significant relationship between ART and carotid artery stenosis. This suggests that the finding of a prolonged ART on FA by itself is not a sufficient reason for recommending carotid ultrasound. Further studies are warranted to evaluate if asymmetric diabetic retinopathy may be a useful prognosticator for carotid artery stenosis.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • vascular occlusion/vascular occlusive disease • retina