Recently, the healthcare community has been abuzz with recent breakthroughs in detecting Alzheimer’s disease in the eye and, potentially, by years earlier than current Alzheimer’s testing. Over the past few years, researchers at Cedars-Sinai have discovered that beta-amyloid plaques commonly found in the brains of Alzheimer’s patients are readily apparent in the retinas of the eyes long before they appear in the brain. This means that patients can potentially be diagnosed and treated much earlier and before symptoms of memory loss appear.
The retinal test, called Retinal Amyloid Index, involves a digital retinal imaging device and an oral supplement called curcumin. Patients are given the curcumin supplement orally and subsequently had their retinas imaged. Curcumin binds to beta-amyloid protein and lights up when viewed with the retinal camera. Resulting retinal images in patients with Alzheimer’s displayed areas of lit bulbs throughout the retina. This test is able to differentiate between Alzheimer’s and non-Alzheimer’s patients with 100 percent sensitivity.
Photo by NeuroVision Imaging
The test is still in development and may not be available in your eye doctor’s office for years. However, there are still options available for monitoring your retinal health.
Nowadays, many eye care providers take photos of your retinas. The retina is a very thin layer of tissue which lines the back wall of the eyes. It receives light, sending electrical signals to the brain to help us see. The retina also contains a vast network of nerves and blood vessels and is intimately connected to the brain. Looking at the retina, we can detect over 300 diseases of the eye and body. For this reason, we would want a baseline photo of the retina so that we can monitor for changes that may develop over time.
In Alzheimer’s disease, besides beta-amyloid plaques in the retina, we can also see changes in the optic nerve, thinning of the blood vessels and changes to the nerve fiber layer (which requires further imaging). Many of these changes mimic other more common eye diseases such as glaucoma or atherosclerotic changes which will need to be ruled out. Be sure to also let your optometrist know if you have a close relative with Alzheimer’s, or have other risk factors for Alzheimer’s such as atherosclerosis, previous head trauma, and poor health and exercise.
Up to now, retinal photos have not played a crucial role in detecting Alzheimer’s disease but I am hopeful that sometime soon, our annual comprehensive eye exams will play a much larger role in preserving the quality of life for these patients. Until then, we will continue to monitor for glaucoma, macular degeneration, high blood pressure, diabetes, and all other diseases that can present in the eyes. The saying goes that the eyes are the window to your soul. I believe that’s true, but it’s also the window to your health. Be sure to see your optometrist annually, a lot can happen in a year.
Cindy P. Wang, OD, FAAO
California Optometric Association