Sunday, January 17, 2010

10.10 Alzheimer's eye test


The headline of The Daily Mirror "High street eye test for Alzheimer's within five years" (Jan 14, 2010) is so tantalizing that prompts a further reading:

"A test for Alzheimer's could be carried out by shop opticians within five years. Scientists have found a way to detect the disease before any symptoms emerge during eye exams.

"By putting harmless fluorescent dye on the retina, they can spot dying cells - an early indication of Alzheimer's.

"The technique could end the need for costly MRI scans.

"Prof Francesca Coredeiro, of University College London, said: "Few people realise the retina is a direct, albeit thin, extension of the brain." and "It's entirely possible a visit to a high-street optician to check your eyesight in five years will also be a check on the state of your brain."

Wow, that is certainly progress; although a careful reading of the original research paper [here] raises some issues:

1. The high-street optician must own and be proficient in operating a confocal scanning laser ophthalmoscope to take the pictures of the retina through dilated pupils plus knowledge in interpreting the images;
2. To put the "harmless fluorescent dye on the retina" requires an intravenous injection of the dye, much like fluorescein angiography; the widely reported eye drops approach simply does not work; and
3. What evidence is there to support death and necrosis of the retinal photoreceptors in mice predates brain cell deaths, and even if true, does that apply to Alzheimer's in humans.

In five years? Maybe not.


BH said...

Very interesting to know this test. Thank you for the post. I've posted the link in already.

EyeDoc said...

Thank you very much. Actually there is already an eye test for Alzheimer's based on protein accumulation in the crystalline lens in the supranuclear zone. This one also requires no contrast agent. It is now in clinical trial.

Opticians Eye Test said...

The researchers found that dead nerve cells in the retina correlate to damage in the brain to such a degree that tests for retinal damage could detect Alzheimer’s.

Opticians Eye Test

EyeDoc said...

There is no problem with the original study. It is the practical application that is questionable. Five years is also too optimistic an estimate as far as clinical trials. Phase I alone will probably take that long.

Luxury Watches For Sale said...

Im not an opthalmologist so I can't give u any comments, but I know this is a good post,...grear job, thanks

Eye Test said...

Our sight can deteriorate very quickly, so it is important that if we are having problems with our eyes, we get them checked as soon as possible. It is better to have an eye test as there is nothing wrong with them, than to suffer with uncorrected vision that may lead to blindness.

Anonymous said...

c'est vraiment un tres bon test