Objective: To investigate systematically the various associated systemic and ophthalmic abnormalities in different types of retinal artery occlusion (RAO).
Design: Cohort study.
Participants: We included 439 consecutive untreated patients (499 eyes) with RAO first seen in our clinic from 1973 to 2000.
Methods: At first visit, all patients underwent detailed ophthalmic and medical history, and comprehensive ophthalmic evaluation. Visual evaluation was done by recording visual acuity, using the Snellen visual acuity chart, and visual fields with a Goldmann perimeter. Initially they also had carotid Doppler/angiography and echocardiography. The same ophthalmic evaluation was performed at each follow-up visit.
Main outcome measures: Demographic features, associated systemic and ophthalmic abnormalities, and sources of emboli in various types of RAO.
Results: We classified RAO into central (CRAO) and branch (BRAO) artery occlusion. In both nonarteritic (NA) CRAO and BRAO, the prevalence of diabetes mellitus, arterial hypertension, ischemic heart disease, and cerebrovascular accidents were significantly higher compared with the prevalence of these conditions in the matched US population (all P<0.0001). Smoking prevalence, compared with the US population, was significantly higher for males (P = 0.001) with NA-CRAO and for women with BRAO (P = 0.02). Ipsilateral internal carotid artery had > or =50% stenosis in 31% of NA-CRAO patients and 30% of BRAO, and plaques in 71% of NA-CRAO and 66% of BRAO. An abnormal echocardiogram with an embolic source was seen in 52% of NA-CRAO and 42% of BRAO. Neovascular glaucoma developed in only 2.5% of NA-CRAO eyes.
Conclusions: This study showed that, in CRAO as well as BRAO, the prevalence of various cardiovascular diseases and smoking was significantly higher compared with the prevalence of these conditions in the matched US population. Embolism is the most common cause of CRAO and BRAO; plaque in the carotid artery is usually the source of embolism and less commonly the aortic and/or mitral valve. The presence of plaques in the carotid artery is generally of much greater importance than the degree of stenosis in the artery. Contrary to the prevalent misconception, we found no cause-and-effect relationship between CRAO and neovascular glaucoma.