OCTA Eye Scan May Detect Sign of Early Alzheimer's Disease
Published : 2018-11-03 - Updated : 2020-01-09
Author : American Academy of Ophthalmology - Contact: www.aao.org
🛈 Synopsis : Results from two studies show that a new, non-invasive imaging device can see signs of Alzheimer's disease in a matter of seconds. The researchers show that the small blood vessels in the retina at the back of the eye are altered in patients with Alzheimer's. Even patients who have a family history of Alzheimer's but have no symptoms show these telltale signs. Optical coherence tomography angiography emerged as a non-invasive technique for imaging the microvasculature of the retina and choroid, and the first clinical studies using this innovative technology were published in 2014.
What is Optical Coherence Tomography Angiography?
Optical coherence tomography angiography (OCTA) is a noninvasive approach that can visualize blood vessels down to the capillary level.
With the advent of high-speed OCT and efficient algorithms, practical OCTA of ocular circulation is now available to ophthalmologists. Clinical investigations that used OCTA have increased exponentially in the past few years. Optical coherence tomography (OCT) has emerged as an important imaging modality in the evaluation and management of retinal diseases.
The noninvasive nature of the test and its ability to image intraocular structures in vivo with resolution approaching that of histological sections has made OCT particularly useful for detection and quantification of macular and optic nerve head pathologies.
Optical coherence tomography angiography emerged as a non-invasive technique for imaging the microvasculature of the retina and choroid, and the first clinical studies using this innovative technology were published in 2014.
Eye Scan May Detect Alzheimer's Disease
Evidence mounts that an eye scan may detect early Alzheimer's Disease, as two new studies suggest signs of the disease are visible in the eyes before symptoms appear.
The researchers show that the small blood vessels in the retina at the back of the eye are altered in patients with Alzheimer's. Even patients who have a family history of Alzheimer's but have no symptoms show these telltale signs. And they showed that they can distinguish between people with Alzheimer's and those with only mild cognitive impairment.
Results from these studies are being presented at AAO 2018, the 122nd Annual Meeting of the American Academy of Ophthalmology.
A new kind of precise and non-invasive imaging called optical coherence tomography angiography (OCTA) has assisted much of the recent research on the eye's connection with Alzheimer's. It enables physicians to see the smallest veins in the back of the eye, including the red blood cells moving through the retina.
Because the retina is connected to the brain by way of the optic nerve, researchers believe that the deterioration in the retina and its blood vessels may mirror the changes going on in the blood vessels and structures in the brain, thereby offering a window into the disease process.
Diagnosing Alzheimer's is Currently a Challenge
Some techniques can detect signs of the disease but are impractical for screening millions of people:
Brain scans are expensive and spinal taps can be harmful. Instead, the disease is often diagnosed through memory tests or observing behavior changes. By the time these changes are noticed, the disease is advanced. Even though there is no cure, early diagnosis is critical as future treatments are likely to be most effective when given early. Early diagnosis would also give patients and their families time to plan for the future.
The goal of this latest research is to find a quick, inexpensive way to detect Alzheimer's at the earliest signs.
Researchers at Duke University used OCTA to compare the retinas of Alzheimer's patients with those of people with mild cognitive impairment, as well as healthy people. They found that the Alzheimer's group had loss of small retinal blood vessels at the back of the eye and that a specific layer of the retina was thinner. Even people with mild cognitive impairment did not show these changes.
Ophthalmologist and lead author Sharon Fekrat, M.D., professor of Ophthalmology at Duke, along with colleague Dilraj Grewal M.D., associate professor of Ophthalmology at Duke, and their research team expect that their work will have a positive impact on patient's lives.
Closeup photo of a human eye.
"This project meets a huge unmet need," Dr. Fekrat said. "It's not possible for current techniques like a brain scan or lumbar puncture (spinal tap) to screen the number of patients with this disease. Almost everyone has a family member or extended family affected by Alzheimer's. We need to detect the disease earlier and introduce treatments earlier."
Because genes play a significant role in how Alzheimer's disease begins and progresses, another team of researchers from Sheba Medical Center in Israel examined 400 people who had a family history of the disease but showed no symptoms themselves. They compared their retina and brain scans with those who have no family history of Alzheimer's.
They found that the inner layer of the retina is thinner in people with a family history. The brain scan showed that their hippocampus, an area of the brain that's first affected by the disease, had already begun to shrink. Both factors, a thinner inner retina layer and smaller hippocampus, were associated with scoring worse on a cognitive function test.
"A brain scan can detect Alzheimer's when the disease is well beyond a treatable phase," said lead researcher Ygal Rotenstreich M.D., an ophthalmologist at the Goldschleger Eye Institute at Sheba Medical Center. "We need treatment intervention sooner. These patients are at such high-risk."
The American Academy of Ophthalmology is the world's largest association of eye physicians and surgeons. A global community of 32,000 medical doctors, we protect sight and empower lives by setting the standards for ophthalmic education and advocating for our patients and the public. We innovate to advance our profession and to ensure the delivery of the highest-quality eye care. Our EyeSmart® program provides the public with the most trusted information about eye health. For more information, visit aao.org
Source/Reference: American Academy of Ophthalmology (www.aao.org). Disabled World makes no warranties or representations in connection therewith. Content may have been edited for style, clarity or length.
Related Alzheimer's Disease Documents
- 1: Is Alzheimer's an Autoimmune Disease? : Brain levels of the lipid ceramide are high in Alzheimer's disease, and now scientists have found increased levels of an antibody to the lipid in their disease model..
- 2: Major Study Into Early Signs of Alzheimer's Disease : Deep and Frequent Phenotyping study hopes to dramatically improve success rate of clinical trials for treatments in Alzheimer's disease.
- 3: Probiotics Improve Memory in People with Alzheimers Disease : Effect of probiotic supplementation on cognitive function and metabolic status in Alzheimer's disease: a randomized, double-blind, and controlled trial.
- 4: OCTA Eye Scan May Detect Sign of Early Alzheimer's Disease : Results from two studies show that a new, non-invasive imaging device can see signs of Alzheimer's disease in a matter of seconds.
- 5: How America Can Cope with Future Alzheimer's Epidemic : The Silverado Story details practices Shook and Winner believe should form the core of America response to the Alzheimers epidemic.
You're reading Disabled World. Be sure to check out our homepage for further informative disability news, reviews, exclusive stories and how-tos. You can also follow Disabled World on social media sites such as Twitter, Facebook, and LinkedIn.
Disclaimer: Disabled World provides general information only. Materials presented are in no way meant to be a substitute for professional medical care by a qualified practitioner, nor should they be construed as such. Any 3rd party offering or advertising on disabled-world.com does not constitute endorsement by Disabled World. View our Advertising Policy for further information. Please report outdated or inaccurate information to us.
Journal: Disabled World. Language: English (U.S.). Author: American Academy of Ophthalmology. Electronic Publication Date: 2018-11-03 - Revised: 2020-01-09. Title: OCTA Eye Scan May Detect Sign of Early Alzheimer's Disease, Source: <a href=https://www.disabled-world.com/health/aging/alzheimers/eye-scan.php>OCTA Eye Scan May Detect Sign of Early Alzheimer's Disease</a>. Retrieved 2021-04-11, from https://www.disabled-world.com/health/aging/alzheimers/eye-scan.php - Reference: DW#187-13579.