Retinal vein occlusion and traditional risk factors for atherosclerosis.

OBJECTIVE To determine whether retinal vein occlusion (RVO) is related to systemic hypertension, diabetes mellitus, and hyperlipidemia. METHODS We systematically retrieved all studies published between January 1985 and July 2007 that compared cases with any form of RVO, including central and branch RVO, with controls. We generated pooled odds ratios (ORs) and estimates of the population-attributable risk percentages for systemic hypertension, diabetes mellitus, and hyperlipidemia. RESULTS Of 21 studies, including 2916 cases and 28 646 controls, both hypertension (OR, 3.5; 95% confidence interval [CI], 2.5-5.1) and hyperlipidemia (OR, 2.5; 95% CI, 1.7-3.7) were significantly associated with any form of RVO; the association was less pronounced for diabetes mellitus (OR, 1.5; 95% CI, 1.1-2.0). Similar results were found in cases with central RVO and branch RVO. The percentage of cases with any form of RVO attributed to hypertension was 47.9% (95% CI, 31.2%-63.1%), to diabetes mellitus was 4.9% (95% CI, 0.8%-11.5%), and to hyperlipidemia was 20.1% (95% CI, 5.9%-43.8%). CONCLUSIONS Hypertension and hyperlipidemia are common risk factors for RVO in adults, and diabetes mellitus is less so. It remains to be determined whether lowering blood pressure and/or serum lipid levels can improve visual acuity or the complications of RVO.