Eye health related to Brain health!

[06/04/2012]

Eye health related to Brain health!

The eye has long been known as the "windows to our souls" and in the medical sense, they are indeed the "windows" through which us eye doctors can observe a lot of disease processes going on!

As a retinal specialist, I find myself very privileged to be able to directly impact on my patients general well being when I examine their retinas because there is a wealth of information that can be obtained by looking at the blood vessels inside which may be an indication of a more widespread systemic problem.

Brief anatomy of the eye

The eye essentially functions like a camera (for those of us old enough to still remember that cameras used to have film in them). The retina is like the film of the camera and it is a very important layer. The retina is full of blood vessels and we can observe disease processes in these blood vessels in systemic diseases such as diabetes, hypertension, anaemia, leukemia, etc.....

The above picture shows how the retina looks like from an observer's point of view.

What is retinopathy?

Retinopathy refers to a group of conditions whereby the common feature would be dysfunction of the retinal blood vessels. In the case of diabetic retinopathy, the presence of excessive levels of sugar in the blood has an adverse effect on the retinal vessels causing them to be more "leaky' and consequently, blood and proteins can leak out causing retinal swelling and reduced vision. There is also insufficient oxygenation of tissue and this results in abnormal "growth" of new blood vessels which are prone to bleeding.

Hypertension can also be associated with retinopathy - blood vessels harden with age and progressive narrowing of vessels and reduced oxygenation can lead to bleeding, swelling and strokes in the eye.

Retinopathy and cognitive decline

There has been a recent study which reported a possible link between the presence of retinopathy and worsening cognitive function in older women. This study looked at over 500 healthy older women (over 65 years of age) as part of the Women's Health Initiative Memory Study and they used retinal photography to assess the eyes of these women, the Mini-Mental State Examination to assess cognitive function over time and also Magnetic Resonance Imaging (MRI) of the brain to look for specific changes.

What they found was that the presence of retinopathy was associated with poorer scores on the mental state test as well as a greater volume of ischemic (oxygen-starved) areas in the brain.

What it means?

The findings of this study adds to a growing body of evidence that diseases of blood vessels has a role in the decline of cognitive function in people. Retinopathy may therefore, be an early marker of small vessel disease in the brain. This could imply that screening the eyes for retinopathy could help detect early vessel disease in the brain and cognitive impairment (dementia) which in turn could be treated early with better effect!

But of course these are still early days yet and further research and studies will be required to evaluate the true relationship between retinopathy and cognitive function. Again another case of "watch this space". Will update further should there be newer information.

Take care of the "windows to your souls"...........