|A new eye test that is simple to perform could help primary care providers effectively diagnose Alzheimer’s disease many years before signs and symptoms show up in patients. That means it may also be possible to conduct medication trials for treating or preventing the progression of the disease, according to new research. .
As reported by United Press International, scientists at the University of Minnesota discovered differences in light pattern reflection of the retinas of mice that progressively changed as they developed Alzheimer’s disease. That suggested to researchers that the ailment could be detected long before symptoms present themselves either to patients or to their doctors.
At present there is no reliable test for Alzheimer’s disease. Currently it is diagnosed from a set of symptoms that present themselves and grow progressively worse over time.
And, while scientists still don’t know exactly what causes the disease, research indicates that amyloid plaque build-up in the brain may be the culprit. Scientists have linked the build-up – which can be detected utilising a special device – to steadily declining mental, memory and cognitive skills as the disease progresses.
Researchers at the Center for Drug Design at the University of Minnesota note that the retina and brain undergo similar changes as a result of Alzheimer’s; they are both connected because they are part of the central nervous system. However, because the retina is readily accessible for examination, the changes there are much easier to detect, UPI reported.
“We saw changes in the retinas of Alzheimer’s mice before the typical age at which neurological signs are observed,” Dr. Swati More, an assistant professor at the Center for Drug Design, said in a press release. “The results are close to our best-case scenario for outcomes of this project.”
In conducting the study, which was published in the journal Investigative Ophthalmology and Visual Science recently, researchers said they built a spectral imaging system that utilised a machine vision camera and tunable wavelength apparatus to measure light reflection of the retinas of test mice.
When comparing the variances in how light was reflected in mice with Alzheimer’s and age-matched wild-type mice that were disease-free between the age of 3 and 8 months, scientists discovered that mice with the disease had reductions in the amount of light that was bouncing off their retinas.
Changes in light reflection indicate a build-up of amyloid in the retina, and therefore, also in the brain. As such, using the technique developed by the University of Minnesota researchers, it is possible to detect the disease long before cognitive and memory declines are seen.
Researchers are planning to begin phase 1 of clinical trials of their retina imaging system with humans. They say they hope eventually to develop an inexpensive diagnosis method that could then lead to effective, early treatment of the disease, instead of simply managing its symptoms.
To treat the disease, Dr. Robert Vince, director of the Center for Drug Design, said patients would have to begin therapy before there were signs of the disease. Until now, he added, the possibility of testing the efficacy of treatment regimens was not possible, because no diagnostic tool existed to measure treatment effects.
“Using currently available detection methods, you have to wait until the plaque is formed to identify Alzheimer’s disease,” Vince said in a press release. “This technology is a non-invasive way to identify Alzheimer’s disease before plaque is formed.”