Retinal photography

Retinal Photography

The technology behind retinal photography has been around for decades, but the knowledge about what it can mean has revolutionised optometric practice. Your retina is the nerve layer at the back of your eye. It contains millions of tiny nerve cells (“rods and cones”) that convert whatever you’re looking at into pinpoints of electricity – these are then shot off to your brain via your optic nerve, and turned into the moving picture of what’s around us. The entire process is instantaneous and extremely clever and complex, and it may be the reason that Charles Darwin said, “The eye to this day gives me a cold shiver.”

When an eye care professional looks into your eye with an ophthalmoscope to examine your retina, the view is generally fairly limited, and we have to move the instrument around to get a good look at everything visible. When we take a retinal photograph:

• we get the “big picture” in one hit,
• we can assess the relationships between retinal blood vessels, and
• we can store the photograph for future comparisons.

So what’s new? What’s the big deal about retinal photography? Put simply, we can now assess your overall cardiovascular profile using simply the blood vessels in your retina. Sound like iridology? Sure does. But it’s nothing to do with your iris, and it’s backed up by medical research. In 2005, a group of ophthalmologists in Melbourne found, with multiple, huge studies, that the way the blood vessels appear inside our eyes gives strong indications of whether people should be paying closer attention to their cardiovascular health. In 2007, they found that these retinal indications are present from an extremely young age (6 years).

In this picture, an artery (the light vessel) is crossing the vein at a right angle, and it’s pinching on the vein as well. Each of these features is seen in individuals who are statistically more likely to develop high cholesterol over time.

Why? We don’t know! It could be that there is a gene that some people have, which causes the crossing changes AND the increased risk of high cholesterol. Does it mean the person will definitely suffer high cholesterol? No, but it does mean they should be vigilant with keeping up to date with cholesterol testing, and if their lifestyle could stand some fine-tuning, it’s a wake-up call. 

This person’s retinal arteries are much skinnier than the veins. Again, for reasons not fully understood, this indicates that the person’s risk of eventually developing high blood pressure is statistically higher than that of other people. There are other signs picked up with retinal photography that pinpoint increased risk of diabetes and stroke.

So what do we do with all this doom and gloom? At ICU our approach is to simply advise our patients of their overall profile, to ensure they know what this means for their overall health testing protocol, and to monitor changes over time. We also give you a copy of your jpg files on CD, in an explanatory folder that summarizes what the findings mean for you. Our approach is to strongly recommend retinal photography to all patients old enough to sit still at the camera. Although this idea took some getting used to with small children and looking at their risk for “adult” diseases, it makes sense for parents to be forewarned. If I knew my children were at greater risk of eventually developing high blood pressure, I’d know to ensure they had an active lifestyle and to (more stringently!) keep them away from junk food, right from an early age!

The other very simple reason we use retinal photography is that it picks up small details that can be missed, that can be important in your overall eye health management. Some people, especially children, are squinty and can’t keep their eyes still when I’m using an ophthalmoscope – an instantaneous flash from the camera gives us images we wouldn’t necessarily have access to otherwise. Our pricing structure for retinal photography is designed to simply help us pay off the camera. We charge $25 (concession $20) for the first round of retinal photography, and then we never charge again, although we use it for all routine visits. It is not the intention of the practice to turn this into a money-making tool – it’s there for better overall eye health management.