Could AMD predict the risk of stroke and cardiovascular disease?
April 1st, 2008
The British Journal of Ophthalmology has published the results of a study undertaken by a team at the University of Sydney in Australia, which assessed the relationship between AMD and the risk of stroke and cardiovascular disease.
The study initially examined 3654 participants with a minimum age of 49 during 1992-1994. Of those, 2335 were then re-examined after 5 years and then 1952 after 10 years. Retinal photographs, medical history and physical examinations were carried out to assess the possible risk factors. Details of death and causes of death were provided and risk ratios were estimated.
The results showed that early AMD among persons younger than 75 years predicted a doubling of cardiovascular mortality rate in the next decade whilst late AMD predicted a 5-fold higher cardiovascular mortality rate and a 10-fold higher stroke mortality rate.
There were various limitations to this study such as the small numbers considered, the inability to adjust the risk ratios for important cardiovascular risk factors and some missing blood profile data. Further study would need to be carried out before this statement can be confirmed and the important implications considered.
Dr Abraham commented: "The characteristic yellow deposits in the macula (the central area of the retinal responsible for detailed central vision) are called drusen and there is evidence that these have cholesterol and other lipids in them and may respond to cholesterol lowering agents. In the Rotterdam study, it was shown in 2004, that high density lipoprotein (HDL cholesterol), but not total cholesterol, as well as the apo E genotype were associated with a small increase in AMD (odds ratio 1.2, confidence interval 1.06 – 1.35) [Am J Ophthalmol 2004;137:750-2]. So it may be that cardiovascular risk factors other than LDL cholesterol (and smoking is known to be one of them) are important in this recently reported association."
