Bill Harvey: The fat of the land

The following headline appeared in the national press this week: ‘Simple eye examination could predict heart attack risk, says study.’

What’s new? I hear you ask. One of the key features of retinal examination is a good look at the retinal arteries and veins to make sure they are of a regular calibre, that arteriovenous crossings are not showing excessive nipping or deviation of the underlying vessel, that the arteriolar surface is not too ‘silvery’ in appearance and, certainly, to rule out any evidence of leakage, such as haemorrhages or signs of oedema. Leakage aside, the other changes I mention are signs of arteriosclerosis, the slow, unevenly distributed degradation in elasticity of vessel walls with age.

Many studies have suggested that the most reliable retinal sign of systemic hypertension is focal narrowing of an arteriole, something likely due to localised retinal oedema. All the other arteriosclerotic signs are best considered along with the age of the patient; you would expect to see them in a 90-year-old, not so a 20-year-old. Also worth remembering is that, if seeing significant tortuosity in a younger patient with otherwise healthy vasculature, always ask if the patient was born pre-term. They usually have been. Avoiding this unnecessary referral for a blood pressure check can be instead taken up by recommending anyone over 50 have one if they have not already done so, irrespective of their retinal appearance.