Alzheimer’s is a progressive neurological condition. It is the most common form of dementia, leading to memory loss, difficulty making decisions and performing daily activities. Common risk factors for Alzheimer’s are aging and genetics. In Alzheimer’s there is a loss and shrinkage of neurons (nerve cells). The hallmarks in Alzheimer’s are the presence of plaques and tangles. The plaques contain a central core of protein known as amyloid. The amyloid protein consists of a protein chain called beta-amyloid. It is believed that beta-amyloid accumulates due to abnormal processing of the amyloid precursor protein molecule. Although there is no cure for Alzheimer’s, current treatments are available to slow the progression of symptoms.
Currently, doctors are using PET (Positron Emission Tomography) and MRI (Magnetic Resonance Imaging) of the brain to detect Alzheimer’s. In the near future, Alzheimer’s disease may be able to be detected during a routine eye exam. The eyes are a sensory organ with direct connection to the brain, via the optic nerve. This will allow Alzheimer’s to be detected much earlier and at a cheaper cost. The early detection can create a group of candidates that can serve in prevention trials.
A study conducted by Australia's Commonwealth Scientific and Industrial Research Organization found the presence of beta-amyloid in the retina. In a study of 200 participants, 40 patients exhibited retinal changes that strongly correlated with amyloid plaque development in the brain. The study will be completed later this year.
A second study SAPPHIRE II, conducted by Cognoptix Inc, found the presence of beta-amyloid in the lens of the eye. This had a strong correlation to PET amyloid brain imaging. Cognoptix is planning on creating a method for primary care clinicians to detect of these amyloid plaques. The method consists of a laser eye scanning device in combination with ophthalmic ointment.
Eye exams are proving to be more important as research progresses. What will they find next?