ACCURACY OF VISIBLE RETINAL EMBOLI FOR THE DETECTION OF CARDIOEMBOLICLESIONS REQUIRING ANTICOAGULATION OR CARDIAC-SURGERY

Aim-To determine the accuracy of visible retinal emboli as a diagnosti c ''test'' for the likelihood of receiving anticoagulation or cardiac surgery based on the results of transthoracic echocardiography, in the setting of acute retinal arterial occlusion. Methods-A multicentre re trospective diagnostic study at Kingston Eye Centre, Queen's Universit y, Kingston, Ontario; Wills Eye Hospital, Philadelphia; Ottawa Eye Ins titute, Ottawa, Ontario; and the Halifax Infirmary, Halifax, Nova Scot ia of 104 patients with both embolic and non-embolic acute retinal art erial obstruction who underwent transthoracic echocardiography was per formed, to determine the accuracy of visible retinal emboli as a diagn ostic ''test'' for anticoagulation or cardiac surgery. Anticoagulation or surgical intervention on the basis of abnormalities was detected s olely through the technology of transthoracic echocardiography. Result s-41 patients had visible retinal emboli (calcific, cholesterol, or fi brin). The remaining 63 had no evidence of embolic disease. The sensit ivity of emboli for the likelihood of a patient receiving anticoagulat ion or cardiac surgery was 50%. The specificity, positive predictive v alue, and negative predictive value were 62%, 15%, and 90%, respective ly. The likelihood ratio (LR=1.31) obtained given the presence of a vi sible retinal embolus was neither clinically nor statistically signifi cant (LR+ve = 1.31; 95% CI (0.91, 3.16)). This likelihood ratio, when applied to a patient with a pretest probability of 50%, results in a p ost-test probability of 56.7%. Conclusions-These results demonstrate t hat the presence of a visible retinal embolus should not be the sole d eterminant of whether to order transthoracic echocardiography, as the likelihood ratio for a patient receiving anticoagulation or cardiac su rgery, given the presence of a visible retinal embolus was only 1.31.