A case-control study of corneal arcus and coronary heart disease in Yerevan

Abstract

Arcus senilis or corneal arcus is a yellowish-white ring around the cornea. It is caused by the extra cellular lipid deposition in the peripheral cornea. Lipids are normally deposited in the cornea, but it is believed that with aging the amount of lipids deposited increases, possibly resulting in arcus senilis. Objective: This study investigated whether corneal arcus can predict coronary heart disease and cardiovascular diseases. Methods: A case-control study was used. The study included 96 participants. Risk factors of coronary heart disease were assessed using a questionnaire. A simple eye examination was completed using an ophthalmoscope. Simple and multiple logistic regressions were used to assess the association between coronary heart disease and corneal arcus. The accuracy of corneal arcus as screening tool to detect coronary heart disease was assessed by calculating sensitivity and specificity. Results: Coronary heart disease was statistically significantly associated with hypertension and corneal arcus. Multiple logistic regression revealed potential confounder such as hypertension. The sensitivity and specificity of using corneal arcus as screening tool for people 35-50 years of age were 19% and 100% respectively. The positive predictive value (PPV) was 100% and negative predictive value (NPV) was 55%. For those over 50 years of age, PPV dropped to 58% while NPV remained 57%. Conclusion: This study presents preliminary results concerning the relationship of corneal arcus and coronary heart disease among people in Yerevan. The accuracy of corneal arcus as screening tool for detecting coronary heart disease limits its worth to clinical settings. Considering the limitations of this study (recall bias and misclassification of visitors as controls) more research is needed to sufficiently assess the influence of selected factors on the relationship between coronary heart disease and corneal arcus.