Risk of Stroke in Patients With Ocular Arterial Occlusive Disorders: A Retrospective Canadian Study

Abstract

Background Monocular vision loss, attributed to either central retinal artery occlusion ( CRAO ), branch retinal artery occlusion ( BRAO ), or ocular ischemic syndrome ( OIS ), is thought to be associated with an increased prevalence of cerebral infarcts. However, there is a paucity of data substantiating this. We aimed to investigate this relationship in a Canadian center and further understand the importance of associated internal carotid artery stenosis in potential clinical decision making. Methods and Results We performed a retrospective cohort study at a comprehensive stroke center of patients presenting initially with CRAO , BRAO , or OIS to a centralized ophthalmology center over a 5-year period. Patients were followed for 3 years for the occurrence of a hemispheric stroke. We identified 83 affected eyes, with 31 CRAO , 35 BRAO , and 17 OIS patients. Before ocular diagnosis, 32.3%, 11.4%, and 41.2% of CRAO , BRAO , and OIS patients, respectively, experienced a symptomatic stroke. Of the remaining patients, 4.8%, 12.9%, and 40%, respectively, suffered a hemispheric stroke within 3 years of ocular diagnosis. Logistic regressions suggested that for CRAO and BRAO patients together, the degree of ipsilateral internal carotid artery stenosis is unable to predict the occurrence of a stroke ( P=0.18), whereas our model correctly predicted a stroke in 82.4% of OIS patients ( P=0.005). Conclusions CRAO , BRAO , and OIS are associated with significantly increased symptomatic stroke rates. Degree of ipsilateral internal carotid artery stenosis may not be useful in risk stratification for these patients, suggesting that they should be triaged appropriately for stroke risk-factor management, independent of internal carotid artery stenosis.

Keywords: Branch retinal artery occlusion; Central retinal artery occlusion; Ocular ischemic syndrome; cerebral infarct; retinal ischemia; stenosis; stroke.

Figure 1

Patient enrollment flowchart. Ninety‐eight patients were identified in our clinical database. Four patients were excluded because of confounding diagnoses (2 for retinal vasculitis, 1 for giant cell arteritis, and 1 for amaurosis fugax). Eleven patients died before the 3‐year follow‐up time point from the diagnosis of CRAO, BRAO, or OIS. None of these deaths were attributed to stroke. Thus, 83 patients were included in the study, with 31 diagnosed with CRAO, 35 with BRAO, and 17 with OIS. BRAO indicates branch retinal artery occlusion; CRAO, central retinal artery occlusion; OIS, ocular ischemic syndrome.

Figure 2

Stroke rates before and after diagnosis of CRAO, BRAO, and OIS. Postdiagnosis stroke rate represents patients with no previous history of stroke or transient ischemic attack. The majority of CRAO patients who had a stroke at some point had it before their diagnosis of monocular vision loss. In BRAO and OIS patients, strokes occurred approximately equally before and after monocular vision loss diagnosis. BRAO inidicates branch retinal artery occlusion; CRAO, central retinal artery occlusion; OIS, ocular ischemic syndrome.

Figure 3

Hazard function of cumulative incident stroke rate after initial diagnosis of CRAO, BRAO or OIS with no previous history of stroke. Log‐rank testing revealed a statistically significant difference between stroke rates (χ²(2)=6.986; P=0.03). BRAO indicates branch retinal artery occlusion; CRAO, central retinal artery occlusion; OIS, ocular ischemic syndrome.

Figure 4

Degree of ICA stenosis ipsilateral to affected eye for CRAO, BRAO, and OIS patients. Of the 31 CRAO patients, 27 had carotid imaging available; 28 of 35 BRAO patients had imaging; all 17 OIS patients had imaging available. The majority of CRAO and BRAO patients had insignificant ipsilateral ICA stenosis. No BRAO patients had ICA occlusion. No OIS patients exhibited moderate stenosis. BRAO indicates branch retinal artery occlusion; CRAO, central retinal artery occlusion; ICA, internal carotid artery; OIS, ocular ischemic syndrome.