retina

Myopia confers protection from diabetes

Myopia confers protection from diabetes 0

The title isn’t clear. Here’s what I mean. If you have myopia, some studies show that you are less likely to get diabetes or you are less likely to have significant diabetic problems. With all the bad things that can happen because a patient has myopia, I can see how the good things might not be reported or seem important. Let me be clear though, having myopia doesn’t mean you won’t get diabetes. It just means you are less likely.

Myopia is also called nearsightedness. It’s not something I have but it’s the most common reason for patients to come to my office. They want glasses or contact lenses usually. That’s mainly why I have a job….people need optical correction to correct their vision. My job is also to check for eye diseases. Those with myopia are at a LITTLE greater risk of some problems and more so if the myopia is high (greater than -5.00). The other guys…the hyperopics (those that are farsighted) have their own¬†LITTLE¬†risks for certain conditions. The other common vision problem easily corrected is presbyopia and I don’t know of any diseases associated with that condition other than losing your reading glasses.

Let me clear up what I mean by risk. If you read a research article and it says the odds ratio for some condition is greater than 1.0, then the risk is higher. If the risk ratio is less than 1.0, then that person is less likely to have/develop the condition than the other group in the study. If the odds ratio is 2.0, then that means twice as many people with myopia will develop that problem than the other group in the study.

In one study I read, a highly myopic person was less likely to develop what’s called proliferative diabetic retinopathy (PDR). Let’s just say, you don’t want to have diabetes AND PDR, period. The odds ratio of having PDR for a younger high myopia person with diabetes was 0.40. That’s lower than 1.0 which means they are less likely of getting PDR. What’s interesting about this is that those with high myopia are at a greater risk for other kinds of retinal problems but in this case, they are at less risk of PDR. It might have something to do with the vascular differences the study said and the extent of a condition called posterior vitreous detachment.

There’s another odds risk for those that have myopia and the likelihood that they will even get diabetes. It was reported as 0.90. That’s less than 1.0. So myopics were less likely to get diabetes compared to the other nonmyopic group in the study.

I should tell you what those bad things are that are more likely to happen in a myopic patient though. The odds ratio varies around 2.0-3.0 for these conditions compared to those with no myopia:

retinal detachment

glaucoma

PSC cataract (that’s not the typical age-related kind of cataract)

macular disease

So, just come in and let me look or get your eyes checked wherever you are. You’re probably fine but you myopes do have a LITTLE greater chance of me finding something there that isn’t good.

I am getting (or have) the complete articles below if anyone wants them.

http://www.ncbi.nlm.nih.gov/pubmed/20031224

http://www.ncbi.nlm.nih.gov/pubmed/8302567

http://www.ncbi.nlm.nih.gov/pubmed/22772022

myopia example

myopia example

 

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Blonde fundus

Blonde fundus 0

I can’t figure out why this phrase even occurred….blonde fundus. I was looking up some other eye things this morning and where the words originated, like Greek or Latin derivations, and wanted to write about this one condition called amaurosis fugax but decided it’s just a bad problem that needed too much of my brain power. So I decided to look up some other things and settled on how we doctors might describe how a retina looks. Usually I just tell a patient that the back of their eye (their retina) was normal and healthy. But for some reason I was taught a special way to describe the appearance of a patient’s retina…probably because I should know that the variations in the appearance of a human retina can vary significantly. So to simply explain what a blonde fundus is, check the color of your hair. If it’s naturally blonde, or long ago it was :), then your retina probably is blonde. But the retina is not really blonde. It just has less pigment in it like your hair. I wish I could say for sure if the two were related to specific genes and I’d bet so.

There are some different layer structures in the retina where you find certain types of cells. You know, rods and cones and stuff. Well there’s a couple of other layers back there called the choroid (pronounced core-oid) and retinal pigment epithelium. I don’t know why there’s epithelium deep in the eye. I always thought epithelium was my skin. Maybe schools teach what our outer skin cells are called first and that just made me not understand what epithelium really is. Whatever the reason, these retinal layers in the eye contain melanin. A smaller amount of melanin means the retina looks redder. Look at the pictures I included below. And yep, in case you wondered, those pictures of red eyes from photographs are showing you, generally, who has the blonde fundus (or plural – fundi). The angle of light has to be just right though to get that red eye effect. Since the red eyes in pictures, or more specifically, the red pupils are the result of the redder color in the retina (red comes from blood) we see this effect reflecting from the camera flash back out of the eye.

Anyway, if your doctor says you have a blonde fundus you’re ok. But if the doctor doesn’t say it, you’re still ok. It’s just something we learned in school so we can call your retina names! Here’s one more name, tigroid fundus. You’re ok if you have that too! Oh, the word fundus is used to describe the bottom or end part of an organ so it’s not just an eye word. Maybe instead of saying bottoms up when we finish our bottled beer we could say fundus up?

blonde fundus

blonde fundus

dark fundus
dark fundus

tigroid fundus
tigroid fundus