How Your Eye Doctor Can “See your high blood-pressure”

Many patients have heard one derivation or another of the same idea — that somehow we as eye doctors can somehow detect a lot of systemic health issues by looking at your eyes. Have you ever wondered how we do it? 

A good place to start is to imagine your body as a series blood vessels, going in size from larger to smaller. In general, most of the major chronic health conditions — high blood pressure, diabetes, atherosclerosis — are chiefly diseases of the blood vessels. When larger blood vessels have a problem, we have well-known names for that. We call them heart attacks, strokes, or liver disease. But what is important to know is that these major problems didn’t start in the big vessels. They began as small abnormalities in the smallest of vessels. 

That presents a problem though. These micro-vessels are all over our bodies, but impossible to see or test. Various forms of medical technology exist to evaluate these major vessels, however to see the health of them at that granular level, there is really only one non-invasive way.

An eye exam.

The blood vessels that supply our retina are the only place to readily see the health of our vascular system, at its most illustrative size, without an autopsy. Our eyes may indeed be the windows to our soul, but they are also the best windows to the health of our vascular system. 

Each time I see a patient’s retina, the first thing I look at is the relative size of the tiny arteries of the retina, versus the veins. Do they have characteristic thinning of the arteries, gaining the appearance of stretched piano wire, indicating chronic high pressure? Have the veins grown thick and non-linear as the body tries to dispel pressure, the same way a river carves up a shoreline during a flood? Do the vessels have microscopic leaks, characteristic of early diabetic retinopathy?

And this is all just from a few seconds looking at the vessels. We still have the other 95% of the retina to look at.