Eyes cells help diagnose Alzheimer’s


Changes to specific cells in the retina could help diagnose and track the progression of Alzheimer’s disease, scientists say.

A team found genetically engineered mice with Alzheimer’s lost thickness in this layer of eye cells.

Alzheimer's brain (left) compared with healthy brain (right)

As the retina is a direct extension of the brain, they say the loss of retinal neurons could be related to the loss of brain cells in Alzheimer’s.

The findings were revealed at the US Society for Neuroscience conference.

The team believes this work could one day lead to opticians being able to detect Alzheimer’s in a regular eye check, if they had the right tools.

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[This] could lead to new ways to diagnose or predict Alzheimer’s that could be as simple as looking into the eyes”

Dr Scott Turner Georgetown University Medical Center

Alterations in the same retinal cells could also help detect glaucoma – which causes blindness – and is now also viewed as a neurodegenerative disease similar to Alzheimer’s, the researchers report.

Scott Turner, director of the memory disorders programme at Georgetown University Medical Center, said: “The retina is an extension of the brain so it makes sense to see if the same pathologic processes found in an Alzheimer’s brain are also found in the eye.”

Dr Turner and colleagues looked at the thickness of the retina in an area that had not previously been investigated. This included the inner nuclear layer and the retinal ganglion cell layer.

They found that a loss of thickness occurred only in mice with Alzheimer’s. The retinal ganglion cell layer had almost halved in size and the inner nuclear layer had decreased by more than a third.

“This suggests a new path forward in understanding the disease process in humans and could lead to new ways to diagnose or predict Alzheimer’s that could be as simple as looking into the eyes,” said Dr Turner.

Alzheimer’s disease

A coloured CT scan image of a human brain
  • Symptoms include loss of memory, mood changes, and problems with communication and reasoning
  • No one single factor has been identified as a cause for Alzheimer’s disease – a combination of factors, including age, genes, environment, lifestyle and general health are implicated
  • One of the leading theories involves the formation of clumps of a protein called beta-amyloid, which damage and kill brain cells

Treatments developed for Alzheimer’s could therefore also be useful for treating glaucoma, he added.

But he also said that so far it was still speculation to say that retinal thinning may predict impending Alzheimer’s disease.

“We’re hoping that this translates to human patients and we suspect that retinal thinning, just like cortical thinning, happens long before anyone gets dementia,” Dr Scott told BBC News.

“Human studies are needed to test this idea as a diagnostic [test]. Current leading biomarkers of Alzheimer’s disease are either very costly or invasive. A retinal thickness scan – as measured by optical coherence tomography – would be both inexpensive and non-invasive.”

Alzheimer’s is a neurodegenerative disease and is the most common type of dementia. The cause is still unknown and there is currently no cure. It often goes undetected for years until so many cells die that symptoms become increasingly prevalent.

But treating the disease early is believed to be vital to prevent memory loss.

Laura Phipps, at Alzheimer’s Research UK, said there was increasing evidence linking retinal cell loss to Alzheimer’s disease, and that it was “positive to see this line of research being followed up”.

“This early-stage study, which is yet to be published in full, was carried out in mice, and further research will be necessary to determine whether changes in the retina found here are also found in people with Alzheimer’s.

“Diagnosing Alzheimer’s with accuracy can be a difficult task, which is why it’s vital to continue investing in research to improve diagnosis methods,” Dr Phipps added.

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New US advice on cholesterol drugs.


A third of all adult Americans should consider taking cholesterol-lowering statin drugs, according to the first such new guidelines in a decade.

It is estimated that 33 million Americans – 44% of men and 22% of women – would meet the threshold for taking statins, under the advice issued by two leading US medical organisations.

File photo of Atorvastatin Calcium tablets, a generic form of Lipitor, which is being sold under a deal with Pfizer.

The drugs are currently recommended for 15% of adults.

The guidelines for the first time take aim at strokes, not just heart attacks.

Under the current advice, statins are recommended for those who have total cholesterol over 200 and LDL, or “bad cholesterol”, of over 100.

But the new recommendations, issued by the American Heart Association and American College of Cardiology, place much less emphasis on setting numerical cholesterol-lowering targets for patients.

The advice introduces a new formula for calculating a patient’s risk of heart disease based on such factors as age, gender and race, instead of high cholesterol levels alone.

“This guideline represents a departure from previous guidelines because it doesn’t focus on specific target levels of LDL, or bad cholesterol, although the definition of optimal LDL cholesterol has not changed,” Dr Neil Stone, author of the report, said in a statement.

It is thought that more women and African-Americans, who are deemed to be at higher risk of stroke, could find themselves taking statins if they follow the guidelines.

The panel focused on four groups they believe statins would benefit most: people already suffering from heart disease; those with LDL levels of 190 or higher because of genetic risk; older adults with type 2 diabetes; and older adults with a 10-year risk of heart disease greater that 7.5%.

The panel also recommended a “diet pattern” based on vegetables, fruits and whole grains and moderate to vigorous exercise three to four times a week for all adults.

Roughly half of those drafting the guidelines had financial ties to makers of heart drugs.

But panel leaders said that no-one with industry connections was allowed to vote on the actual recommendations.

“It is practically impossible to find a large group of outside experts in the field who have no relationships to industry,” Dr George Mensah, of the AHA, told the Associated Press news agency.

He said the guidelines were based on solid evidence.

Many of the patents on popular statins, such as Lipitor and Zocor, have expired, with generic versions being offered cheaply.

But Crestor, a statin made by AstraZeneca, remains under patent, with sales of $8.3bn (£5.2bn) in 2012.