The brain plays an essential role in integrating the visual information our eyes gather, transforming it into comprehensible images. This interaction between brain and eye tissues is a field of great interest to ophthalmologists and neurologists. In this article, with the help of specialists from Clínica Nivaria in Santa Cruz de Tenerife, we'll share several interesting facts:
How are neurological diseases related to the eye?
Research suggests that brain diseases and conditions can also affect the eyes, since the optic nerve and retina are extensions of brain tissue outside the skull. Diseases such as Alzheimer's and other forms of dementia, caused by damage to brain cells, have been observed to have effects on the retina.
Although we do not yet have eye tests that allow us to fully diagnose or understand dementia, current research shows promising potential. Studies highlight the direct relationship between brain tissue and eye tissue, pointing to future avenues for research.
Is it possible to detect Alzheimer's disease through the eyes?
Alzheimer's disease is characterized by an abnormal buildup of proteins in the brain, which destroys cells and damages the connections between neurons. Common symptoms include memory loss, difficulty reasoning, disorientation, and cognitive decline, and can also affect vision, particularly spatial and depth perception. Some patients have trouble reading, tracking moving objects, or distinguishing contrasts.
There are several types of dementia, with Alzheimer's being the most common. It accounts for 60 to 80% of all cases. Some people develop mild cognitive impairment (MCI) in old age, which may or may not worsen over time and can be an early stage of Alzheimer's.
Currently, Alzheimer's is diagnosed after a series of evaluations that rule out other causes. These may include cognitive tests, consultations with family members, physical examinations, and brain scans. However, these tests alone do not confirm Alzheimer's; a definitive diagnosis can only be made post-mortem through examination of brain tissue.
The difficulty in diagnosing Alzheimer's and other dementias is driving research into the eye-brain connection. What if a detailed analysis of the retina could help identify brain diseases in their early stages? Eye exams are already known to diagnose systemic health problems such as cardiovascular disease, diabetes, high blood pressure, autoimmune diseases, sexually transmitted infections, and some cancers.
New research opens promising avenues
Recent studies indicate changes in the retina of people with Alzheimer's or other dementias. Although these are preliminary studies, they pave the way for broader research. Most of these studies have identified changes in individual layers of the retina or in blood flow within the eye.
Many of these retinal changes are detected using a quick and common test called optical coherence tomography (OCT), routinely performed by our ophthalmologists. However, the full technology for this type of test is not yet available.
Another recent study used a new imaging technique called fluorescence lifetime ophthalmoscopy (FLIO) to measure a protein called beta-amyloid in the retina, which is associated with Alzheimer's disease. Studies also show changes in eye tissue in people with other brain diseases such as Creutzfeldt-Jakob disease (mad cow disease) and Parkinson's disease.
For patients, continue with routine eye care.
Although studies are encouraging, there is still not enough information about the eye-brain connection to change the approach for patients. If you are concerned about memory loss or dementia, consult your primary care physician or a neurologist. If you have any concerns about your vision or eyes, we welcome you to our Ophthalmology Clinic in Santa Cruz de Tenerife.
We look forward to seeing you at our Ophthalmology Clinic located in Santa Cruz de Tenerife. Contact us and schedule an appointment with one of our professionals. You'll receive the best ophthalmological care in the Canary Islands!
