Abstract
Purpose: :
It is known that traditional cardiovascular risk factors predispose individuals to retinal vein occlusions (RVO). Yet the future risk of developing cardiovascular disease in patients with RVOs is uncertain. The Framingham Risk Score is a validated measure of estimating the 10-year risk of developing cardiovascular disease (e.g., coronary artery disease, myocardial infarction, angina pectoris, cerebrovascular disease, peripheral vascular disease). We performed a literature review and meta-analysis of studies to determine the 10-year Framingham risk for individuals with RVO.
Methods: :
A literature search was performed in MEDLINE and EMBASE. Studies were eligible if they included subjects with RVO and presented data on: age, sex, smoking status, systolic blood pressure, total cholesterol and high-density lipoprotein. The 10-year Framingham risk was calculated. Sensitivity analysis was performed using sex and smoking status variables. Hypothesis testing was carried out using the upper tail z-test with α= 0.05 to compare the estimated Framingham risk in RVO patients with the risk in the general Canadian population. Sub-group meta-analysis was carried out by the Cochrane Collaboration RevMan 4.5 software. Quality assessment was carried out using the Newcastle-Ottawa Scale (NOS) for case-control studies and the Downs and Black instrument was applied to cross-sectional studies. PRISMA (Preferred Reporting Items in Systematic Reviews and Meta-Analyses) flow diagram was used to document the flow of studies throughout different phases of the review.
Results: :
408 abstracts were screened and 24 underwent full-text screening. A final list of 6 articles were included. The two case-control studies were found to be of moderate quality. The 4 cross-sectional studies had Quality Indices of 12, 14, 15 and 15. The estimated 10-year Framingham risk score in subjects with RVO was 10.1% (95% CI: 9.9, 10.2). The Framingham risk in subjects with RVO was significantly higher than the general Canadian population risk which is 6.0% (p<0.0001). Sensitivity analysis found FRS to be greatest in male smokers at 27.8% (95% CI: 27.7, 27.9) followed by male non-smokers at 17% (95% CI: 16.9, 17.1). In a sub-group analysis, the 10-year risk was significantly higher in subjects with RVO compared to controls (difference in % risk = 2.74; 95% CI: 2.56, 2.91).
Conclusions: :
Patients with RVO have an increased 10-year risk of cardiovascular disease. This risk is greatest for male smokers (high risk). These patients may benefit from therapy aimed at controlling their risk factors. Additionally, individuals sustain RVO when FRS exceeds 10.1% and should be cautioned about the possibility of vision loss from RVO.
Keywords: vascular occlusion/vascular occlusive disease • clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: outcomes/complications