Does a visible retinal embolus increase the likelihood of hemodynamically significant carotid artery stenosis in patients with acute retinal arterialocclusion?

Objective: To determine the value of visible retinal emboli as a diagnostic "test" for the detection of hemodynamically significant carotid artery ste nosis in the setting of acute retinal artery occlusion. Methods: A cross-sectional diagnostic accuracy study was performed in a ter tiary North American center, with the results of the dichotomous diagnostic test (the presence or absence of visible retinal emboli) being placed agai nst the dichotomous outcome of the presence or absence of hemodynamically s ignificant carotid artery stenosis (defined as greater than or equal to 60% , or <60%, carotid artery stenosis on either side). Results: Forty-eight (18.7%) of our 256 patients had hemodynamically signif icant carotid artery stenosis. The sensitivity and specificity of retinal e mboli for the detection of hemodynamically significant carotid artery steno sis were 39% and 68%, respectively. The presence of a visible retinal embol us generated a likelihood ratio of 1.24 (95% confidence interval, 0.84-1.86 ). This value corresponds to a patient with a pretest probability of 50% ha ving a posttest probability of 55.3%. The absence of a visible retinal embo lus generated a likelihood ratio of 0.88 (95% confidence interval, 0.68-1.1 5). Conclusions: The presence of a visible retinal embolus is a poor diagnostic test for the detection of hemodynamically significant carotid artery steno sis in the setting of acute retinal artery occlusion. Accordingly, the pres ence of an embolus should not influence the decision to perform carotid Dop pler ultrasonography in patients with acute retinal arterial occlusion.