Leading expert in neurodegeneration and eye disease, Dr. Francesca Cordeiro, MD, explains how the DARC eye drop test detects early Alzheimer's disease by identifying dying retinal cells, offering a potential non-invasive and cost-effective diagnostic method up to two decades before clinical dementia symptoms appear, with a Phase 2 clinical trial now underway.
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Early Alzheimer's Diagnosis with a Simple Eye Test
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- DARC Technology Explained
- Link Between Retina and Brain
- Clinical Trial and Down Syndrome
- How the Eye Test Works
- Apoptosis as an Early Biomarker
- Future of Alzheimer's Diagnosis
DARC Technology Explained
DARC technology, which stands for Detection of Apoptosing Retinal Cells, is a novel diagnostic approach for early Alzheimer's disease detection. Dr. Francesca Cordeiro, MD, developed this method to identify nerve cell death in the retina. The core principle is that this retinal cell death mirrors the neuron cell death occurring in the brain during neurodegenerative processes.
This technology represents a significant shift from traditional, more expensive diagnostic tools like MRI or PET scanners.
Link Between Retina and Brain
The eyes truly are a window into the brain, providing a non-invasive view of central nervous system health. Dr. Francesca Cordeiro, MD, emphasizes that diagnosing Alzheimer's disease early can make a profound difference in patient outcomes. The retinal nerve cells are an extension of the brain, sharing similar structures and vulnerabilities.
Changes observed in the retina's synapses occur simultaneously with synaptic changes in the brain, making it a reliable indicator of neurological health.
Clinical Trial and Down Syndrome
A Phase 2 clinical trial for the DARC technology is starting to validate its use in Alzheimer's diagnosis. Dr. Francesca Cordeiro, MD, explains the trial will include a group of patients at high risk for Alzheimer's disease: individuals with Down's syndrome. These patients have an extra chromosome that leads to over-expression of beta amyloid protein.
Beta amyloid is the same protein implicated in the brain plaques of Alzheimer's disease. Consequently, Down's syndrome patients have a very high rate of dementia, making them an ideal group for studying early detection methods.
How the Eye Test Works
The DARC test procedure is straightforward and minimally invasive for patients. A special fluorescent dye is injected into the patient's arm, which then circulates through the bloodstream. Medical professionals then take photographs of the back of the eye using equipment similar to what optometrists use for routine eye examinations.
Dr. Anton Titov, MD, notes the significance of using relatively inexpensive machines compared to complex neurological imaging equipment. The fluorescent dye specifically binds to and identifies retinal nerve cells that are undergoing apoptosis, or programmed cell death.
Apoptosis as an Early Biomarker
Apoptosis serves as a crucial early biomarker for both Alzheimer's and Parkinson's disease. According to Dr. Francesca Cordeiro, MD, experimental data shows retinal cell apoptosis occurs very early in the disease process, long before full-blown symptoms develop. In glaucoma, retinal cells show apoptosis before the eye disease becomes clinically apparent.
Transgenic mouse models provide strong evidence that retinal cell apoptosis is an early event that parallels brain changes in neurodegenerative conditions.
Future of Alzheimer's Diagnosis
The potential of DARC technology could revolutionize how we approach Alzheimer's diagnosis and monitoring. Dr. Anton Titov, MD, discusses how this method might diagnose the subclinical state of Alzheimer's disease up to 20 years before clinical manifestations of dementia develop. This early detection window could allow for interventions at a stage when they might be most effective.
Dr. Francesca Cordeiro, MD, and her team are working to prove this concept through ongoing clinical trials that will further validate the connection between retinal apoptosis and brain neurodegeneration.
Full Transcript
DARC technology, Detection of Apoptosing Retinal Cells, relies on finding nerve cell death in the retina. It means nerve cells are dying in the brain too. People at high risk of Alzheimer’s disease may benefit.
The eyes are the window into the brain. It's clear that diagnosing Alzheimer's disease reasonably early would make a very big difference.
Dr. Anton Titov, MD: You developed a particular eye diagnostic test. It can be used to potentially pinpoint patients at higher risk of Alzheimer's disease. You can diagnose a subclinical state of Alzheimer’s disease. You can diagnose it up to 20 years before the clinical manifestations of dementia develop.
Dr. Anton Titov, MD: Could you please discuss the eye test for Alzheimer’s disease that you developed?
Dr. Francesca Cordeiro, MD: Sure! This is the DARC technology, Detection of Apoptosing Retinal Cells. It relies on the fact that you get cell death in the retina mimicking neuron cell death in the brain.
Dr. Francesca Cordeiro, MD: At the moment we haven't done patients with Alzheimer's disease. Our Phase 2 clinical trial is starting here next month. It does contain a group of patients who are at high risk of Alzheimer's disease.
Dr. Francesca Cordeiro, MD: They will be having this diagnostic test for glaucoma and Alzheimer’s disease. These patients have Down's syndrome. In Down syndrome there is an extra chromosome.
Dr. Francesca Cordeiro, MD: What's believed to happen is this. As Down's patients are living longer, it is known that they have a lot of beta amyloid protein. Beta amyloid protein is implicated in the plaques in the brain in Alzheimer's disease.
Dr. Francesca Cordeiro, MD: They over-express this beta amyloid. So there's a very high rate of dementia in Down’s syndrome patients. We are going to look at this sample of patients.
Dr. Francesca Cordeiro, MD: We will use DARC. DARC basically involves an injection into the arm of special dye. Then we take photographs of the back of the patient’s eye.
Dr. Francesca Cordeiro, MD: It is very similar to machines that you see being used to examine your eye. This is done when you go to optometrists and opticians. The importance of that is these are fairly cheap machines to examine an eye.
Dr. Francesca Cordeiro, MD: You compare it to an MRI or a PET scanner. But they allow you to diagnose abnormality. Because the dye that is injected into your arm is a fluorescent dye.
Dr. Francesca Cordeiro, MD: It identifies those nerve retina cells that are dying through apoptosis. We do know that from all our experimental data or the medical literature.
Dr. Anton Titov, MD: Apoptosis in itself is very important in Alzheimer's disease and in Parkinson’s disease. You see apoptosis as an early stage sign of Alzheimer’s disease and of glaucoma.
Dr. Anton Titov, MD: Retinal cells have apoptosis before you develop the full blown glaucoma eye disease. Obviously you need to prove this.
Dr. Francesca Cordeiro, MD: We will be doing that at the clinical trials going forward. But certainly, you go to our transgenic experimental mouse models. There is very good evidence that retinal cells apoptosis.
Dr. Francesca Cordeiro, MD: It is a very early event. Nerve cell death in the retina mimics almost all the changes you see in the synapses of the brain.
Dr. Francesca Cordeiro, MD: At the same times you see a change in synapses in the brain, you're also seeing apoptosis in the retina.