Amyloid plaque build up in the brain is a significant characteristic of Alzheimer's disease. New non-invasive optical imaging technology, developed at Cedars-Sinai, is being evaluated in ongoing clinical trials in the United States and in Australia. The study of this optical imaging technology to find the amyloid plaques originated at Cedars-Sinai with preclinical studies and postmortem investigations of the retinas of AD patients.
The purpose of the trials is to ascertain whether researchers are able to correlate retinal plaque, found by optical imaging, with brain plaque found in PET (positron emission tomography) scans. Current tests only indicate the changes in the brain have taken place once the disease has already progressed to an advanced stage. Early detection could be critical as alternative treatment options become available and may offer the opportunity to change the course of the disease.
The clinical trial in Australia is being conducted at the Commonwealth of Scientific and Industrial Research Organisation. The approximately 200 volunteers participating in the study were divided into three groups: participants already diagnosed with AD, participants diagnosed with mild cognitive impairment and a control group with no indications of any brain dysfunction. Early results from the Australian clinical study indicate that the non-invasive imaging test can differentiate Alzheimer's disease with total sensitivity and roughly 80% specificity. The plaques in some study patients are currently being followed by trial researchers as part of the study.
Dr. Keith L. Black, MD, chair of the Cedars-Sinai Department of Neurosurgery, director of the Maxine Dunitz Neurosurgical Institute and Ruth and Lawrence Harvey Chair in Neuroscience stated "The device we developed enables us to look through the eye - Just as an ophthalmologist looks through the eye to diagnose retinal disease - and see these changes." Black continued "PET scans require the use of radioactive tracers and cerebrospinal fluid analysis requires invasive and often painful lumbar punctures, so neither approach is feasible as a screening technique, especially for patients in the very early stages of the disease." Shaun Frost, a biomedical scientist and the study manager at the Commonwealth Scientific and Industrial Research Organisation, indicated that the optical imaging exam employed in the study seems to be able to ascertain changes that occur some 15 to 20 years before traditional clinical diagnosis.
Investigations as to whether or not the imaging device can offer comparable results in patients already living with AD are now being studied at both the University of San Diego & Emory University in Atlanta.
This new retinal test is not yet available to the public.