Ocular and Systemic Findings and Their Correlation with Hemodynamically Significant Carotid Artery Stenosis: A Retrospective Study

BACKGROUND: Optometrists often encounter patients with ocular signs and/or symptoms suggestive of carotid artery disease, but criteria for eye care practitioners concerning when to order carotid studies are not well established. A retrospective study in an optometry clinic was performed to determine if certain ocular findings and associated systemic risk factors were associated with hemodynamically significant carotid artery stenosis (HSCAS). METHODS: A retrospective analysis was performed on all patients examined in the optometry clinic at the Sepulveda Ambulatory Care Center from January 1, 1998 through December 31, 1999 to identify all patients who had carotid studies ordered. Charts were then reviewed to determine the ocular finding that prompted the carotid study. Statistical analysis using an odds-ratio was performed to determine whether any ocular sign/symptom or systemic risk factor was associated with HSCAS. RESULTS: Of 3822 patients, 48 (1.26%) had carotid studies ordered. Eight (17%) had HSCAS of >50% and symptomatic patients were 1.6 times more likely to have HSCAS than asymptomatic patients. Patients with HSCAS were 1.8 times more likely to have retinal vascular occlusions, 1.9 times more likely to have normotensive glaucoma, 2.4 times more likely to have peripheral retinal hemorrhages, and 2.6 times more likely to be smokers, although none of these factors were found to be a statistically significant indicator of HSCAS. However, the number of systemic diseases tended to be greater for the HSCAS patients compared with the non-HSCAS patients (HSCAS median = 3.5 and the non-HSCAS median = 2, p = 0.049). CONCLUSION: Although no single ocular or systemic risk factor was found to be a statistically significant indicator of HSCAS, the number of systemic disease risk factors tended to be greater for the HSCAS patients compared with the non-HSCAS patients (p = 0.049). An extensive literature review was also performed to help establish guidelines for when to order carotid studies on the basis of ocular signs and/or symptoms as well as the presence of additive associated systemic risk factors.