Retina Blood Vessels Predict Common Fatal Diseases

An anonymous reader writes "LiveScience is reporting that Tien Wong, of the Center for Eye Research Australia at the University of Melbourne, is claiming that abnormalities in the blood vessels of the retina can be used to predict diabetes, hypertension, stroke, and heart disease. These results were the culmination of several large studies. This could go a long way towards advancing medicine in the developed world as these disorders are some of the most common causes of death, hospitalization, and disability."

Comments

Opthamologists knew this already...

[dudeX]

When I first went to a good eye doctor in 2002, she told me that the retina can tell a lot about a person's general health. She claimed she saved several patients lives when she found cholestorol build up in the vessels of the eye.

Nevertheless this is a good nonintrusive way to diagnose someone.

this has been done for years!!!

[tbird81]

Doctors have been looking at retinas for years! It's well known they're a (relatively) easy way to get a look at small blood vessels.

Microhaemorrhages (bleeds) and aneurysms (a bulging section of a vessel) may be present due to hypertension in the vessels because of diabetic changes to the retinal vessels, or systemic hypertension. Having more blood vessels than usual indicates that the existing ones are not supplying enough oxygen, as will be the case in advanced diabetes. Changes in the macular (the part of the eye that sees most detail) can be apparent if the diabetes is causing problems with vision.

Stroke, heart disease, hypertension and atheroscelerosis are all intimately linked anyway - people at risk of one are often at risk of others. And it's difficult to characterise the changes to a specific cause. But they're still an important thing to look at.

Another time a doctor will look at the retina, is in an emergency situation where the is a blow to the head, they'll look for papilloedema (a swelling behind the retina due to increased pressure inside the skull). This also happens with other causes of high intracranial pressure, such as tumours.

Re:Iridology

[penthouseplayah]

There is the Keyser-Fleischer ring (cupper deposits) that can be seen in the outer rim of the iris in Wilsons Disease (deficit in cupper metabolism). Although often times the ring is not seen after diagnosis has been made by blood tests. The disease is fatal unless treated, and also has a high rate of neurological deficits if treatment is initiated too late.

Chinese Medicine

[LuYu]

This is text book Chinese medicine. Looking for signs of these things in the face and eyes has a history of about 1500 to 2000 years. I guess it is good that Western medicine has finally come around, but this is far from amazing.

Re:One test for everything?

[nanoakron]

You raise a good point, but the problems are severalfold.

First, you need to identify the disease you're looking for.
Next, you go to the lab and spend lots and lots of time looking to develop a test that is both sensitive and specific for that disease.

A couple of definitions:

Specific - Only picks up that disease (in reality, a test with a low false positive rate)

Sensitive - Able to detect that disease every time it's there (a low false negative rate)

Take prostate cancer for example.

In laymans terms many people think the following:

Some cells of the prostate produce PSA (prostate specific antigen). If the PSA level is raised this means cancer.

A urologist thinks:

This patient has a raised PSA. Many conditions other than prostate cancer can produce elevated PSA including infections, trauma and masturbation. Also, some prostate cancers don't produce elevated PSA. So, what's the chance this one-off screening test showing a mildly elevated PSA means this patient has cancer? Also remember that this result is distributed along a normal curve and may simply represent what is normal for this particular patient despite being high against the population as a whole.

And that's the problem.

1) Identifying a test-able target molecule(s)
2) Screening the population at large to define normal limits. Recognising 5% of patients fall outside these limits given a normal distribution curve
3) Finding what conditions other than your specific disease cause an elevation in your marker molecule(s)
4) Finding the number of patients who have your disease but don't produce your marker molecule(s)

So the actual testing of a target, once defined and fully catalogued, is actually the easiest part of the process given modern analytical techniques.

It's the thousands of man-hours of lab work, research PhDs and patients involved in defining a test to begin with that's prohibitive.

And that's why many rarer diseases don't have simple tests to uncover them. It's also why your doctor will produce a whole battery of tests before giving you a definitive diagnosis.

It's not because we're procrastinating or not willing to tell you the answer.

-Nano.

Why check ears? To see nasal infection/congestion

[KWTm]

Well, checking the ears won't identify "the runs" (diarrhea), but I routinely check patients' ears if they give a history of cough, headache, pink eye, or other head/neck symptoms. This is to help identify nasal congestion, a common cause of head/neck problems. Fluid (normally) produced in the sinuses, middle ear (behind the eardrum, so it can't come out through the eardrum), and eyes (excessive amounts would be called "tears") all normally drain into nasal cavity. If your nose is plugged, then you'd get sinus fluid buildup causing sinus headache, ear fluid buildup causing plugged and sore ears, and failure to adequately lubricate the eyes causing irritation and possibly infection. Furthermore, if your nasal mucus is running down the back of your throat, the "post-nasal drip" can cause a cough that won't go away with cough medicine. But try a decongestant, and the cough medicines will magically start working.

When I look in the ears, I can see whether there is fluid behind the eardrum, and tympanic bulging, which tells me that the eustachian tube (and therefore the nose) is plugged. If it is, then I can predict that the patient will probably have the sinus/eye/cough symptoms mentioned above. So the conversation would be more like:

P: I've got a cough and a headache.
D: Let me look in your ears. Yup, you've got a cough and headache.

By the way, about half my patients don't believe me when I tell them about their nasal congestion, because there's no mucus running out the nostrils, and their nose is unplugged enough so that they can breathe ok. Doesn't mean the eustachian tube's not blocked.

It's already being done...

[S.O.B.]

For the past couple of years my eye doctor has used a device called "Optomap" (http://www.optomap.com/) to capture a digital image of my retina. The first time he used it he identified that I had hypertension, which I had been diagnosed with a number of years before, and can even track it's progress. Had this device been in use before I was diagnosed my hypertension might have been caught earlier.