Current issues of ACP Journal Club are published in Annals of Internal Medicine


Prognosis

Corneal arcus predicted mortality from coronary heart disease and cardiovascular disease in young white men

ACP J Club. 1991 May-June;114:88. doi:10.7326/ACPJC-1991-114-3-088


Source Citation

Chambless LE, Fuchs FD, Linn S, et al. The association of corneal arcus with coronary heart disease and cardiovascular disease mortality in the Lipid Research Clinics Mortality Follow-up Study. Am J Public Health. 1990 Oct;80:1200-4.


Abstract

Objective

To examine the relation between corneal arcus and mortality from coronary heart disease (CHD) and cardiovascular disease.

Design

Secondary analysis of data collected on a cohort of men and women with elevated cholesterol and triglyceride levels participating in the Lipid Research Clinics Mortality Follow-up Study.

Setting

10 lipid research clinics in the United States and Canada.

Patients

A 15% random sample of 60 502 persons screened for plasma levels of cholesterol and triglycerides, plus all patients with high cholesterol or triglyceride levels and those taking lipid-lowering drugs, plus varying proportions of those with borderline elevation of cholesterol or triglyceride, were invited for a more extensive evaluation. For this secondary analysis, participants were excluded if they had possible or definite CHD at baseline, were black, were using lipid-lowering medications; or were women who used estrogens or progestogens, or were pregnant. The final cohort included 3930 men and 2139 women (age range, 30 to 69 y). Vital status was determined annually, for a mean of 8.4 years, for 99% of participants.

Assessment of prognostic factors

Trained interviewers (using a standard protocol) identified corneal arcus by a single examination, without using a slit lamp. All uncertain diagnoses were classified as negative.

Main outcome measure

Mortality from CHD or cardiovascular disease.

Main results

Corneal arcus was associated with mortality from cardiovascular disease in men who were hyperlipidemic and aged 30 to 49 years; the relative hazard ratio for cardiovascular disease was 4.0 (95% CI 1.2 to 12.9), after adjusting for age, total cholesterol, HDL-cholesterol, and smoking. Corneal arcus was associated with mortality from CHD in men with high lipid levels who were aged 30 to 49 years (hazard ratio 3.7, CI 0.9 to 14.7). Independent of its association with hyperlipidemia, corneal arcus was as strong a predictor of CHD or cardiovascular disease among 30- to 49-year-old men as other common risk factors, such as ischemia on resting electrocardiogram and family history of heart disease. Corneal arcus did not predict CHD mortality among men or women 50 years of age or older.

Conclusion

Corneal arcus may be an independent predictor of mortality from coronary heart disease and cardiovascular disease in white men between 30 and 49 years of age.

Source of funding: National Heart, Lung, and Blood Institute.

Address for article reprint: Dr. B.M. Rifkind, Lipid Metabolism-Atherogenesis Branch, NHLBI, National Institutes of Health, Federal Building, Room 401, Bethesda, MD 20892, USA.


Commentary

The relation between corneal arcus and mortality from CHD and cardiovascular disease has been reported previously. Corneal arcus as an independent predictor of CHD has, however, been debated.

Additional evidence of the association of corneal arcus and mortality from CHD and cardiovascular disease in white men between 30 and 49 years of age must be provided before the practicing physician uses corneal arcus as a prognostic factor. First, only 56 deaths were included in the analysis for the participants who were between 30 and 49 years of age at the initial visit. Because of the small sample size, the estimates of relative hazard of CHD or cardiovascular disease mortality were not statistically significant for the normolipidemic participants or for the hyperlipidemic participants for CHD. In addition, the clinical assessment for corneal arcus was not verified by a slit-lamp examination, nor was the clinical diagnosis tested for reliability with repeat examinations.

Before corneal arcus is used as a prognostic indicator for CHD and cardiovascular disease, prospective studies designed with the relation of corneal arcus and cardiovascular disease as the primary research question should be done. Such studies should include definitive diagnoses of corneal arcus.

Claudia A. Kozinetz, PhD, MPH
Baylor College of MedicineHouston, Texas, USA.