Parkinson’s disease is a neurodegenerative disorder that affects Dopaminergic neurons, which are nerve cells in the brain responsible for producing dopamine. Dopamine functions as a neurotransmitter...
With research we keep hearing of new and improved ways of diagnosing health concerns and illnesses. Honor Whiteman has published information on yet another big concern around the world, Alzheimer’s. Wouldn’t it be great if something as simple as an optical imaging system could detect this horrible and debilitating disease?
Researchers have revealed how a noninvasive, high-resolution imaging technique was able to detect beta-amyloid plaques in the retinas of patients with Alzheimer’s disease. The co-author of the study is Maya Koronyo-Hamaoui, Ph.D., of the Maxine Dunitz Neurosurgical Institute at Cedars-Sinai in Los Angeles, CA. She and her colleagues have recently reported their findings in the journal JCI Insight.
This is the most common form of dementia and accounts for about 60 to 80% of the cases. The symptoms and characterizations of Alzheimer’s are problems with memory and thinking, as well as changes in mood and behavior. Most often these become more severe over time. There are currently 5.5 million people estimated in the US alone that are living with this disease. In fact, it is reported that every 66 seconds a person in the US is diagnosed with the disease.
It is known that the condition involves the degeneration and death of brain cells where the buildup of a protein called beta-amyloid is considered a key culprit in the process. This is a sticky fragment of the amyloid precursor protein that resides in the fatty tissue around the brain cells, or neurons. These beta-amyloid fragments clump together and form plaques in the brain that disrupt the neuronal communication and trigger immune cell activity leading to inflammation and brain cell death.
These plaques are considered a hallmark of Alzheimer’s and the professionals use positron emission tomography or cerebral fluid analysis to detect the presence of beta-amyloid and make an Alzheimer’s diagnosis. Such techniques are not only invasive, according to Dr. Koronyo-Hamaoui, but is limited and the costs are high, making population-wide screening challenging.
According to recent studies beta-amyloid can be detected in the retina. This is the light-sensitive tissue that lines the back of the eye and sends signals to the brain. Dr. Koronyo-Hamaoui and her team tested the efficacy of a novel retinal imaging technique for identifying beta-amyloid deposits and the diagnosing of Alzheimer’s disease. This involves auto fluorescent imaging of the retina using an especially designed ophthalmic camera and state-of-the-art image processing software. Sixteen Alzheimer’s patients and age-matched controls were tested with the imaging method. They report the retinal imaging technique identified a 4.7X greater abundance of beta-amyloid plaques in the retinas patients with Alzheimer’s disease, compared with the retinas of the controls.
Retinas of 23 deceased patients who had Alzheimer’s disease and retinas of 14 age-matched deceased individuals who did not have the disease were tested on this method. This still revealed a higher abundance of beta-amyloid plaques in the retinas of Alzheimer’s patients than in those of the controls. They were also able to find that both the living and deceased patients with the disease have neuronal loss in the retinas as a result of beta-amyloid plaques that correlated with neuronal loss in the patients’ brains.
This may lead to a practical approach for large-scale AD diagnosis and monitoring. They plan to test their technology in further clinical trials to eventually bring retinal imaging to the forefront of Alzheimer’s diagnosis.
Dr Fredda Branyon