As researchers look for better ways to diagnose Alzheimer’s disease in its early stages, one promising detection methodology to emerge is a simple eye tracking procedure developed by scientists at Lancaster University in conjunction with Royal Preston Hospital. The results of such tests can help flag initial signs of memory impairment that are associated with the onset of the disease.

The study involved 19 Alzheimer’s patients, 25 patients suffering from Parkinson’s disease, 17 older people and 18 healthy young people. Participants were asked to follow the movement of light on a computer monitor and occasionally asked to look away from the light.

The researchers found that patients with Alzheimer’s made no errors when they were asked to look towards the light, but did make errors that they were unable correct when they were asked to look away.

The errors that the Alzheimer’s patients could not correct were 10 times more frequent than in the other groups. The researchers also measured memory function among those Alzheimer’s patients who found the test difficult and the tests showed a clear correlation with impaired memory capability.

It's hoped that the findings of the research will improve the prospects of diagnosing the disease. Current methods depend on complex neuropsychological tests that can be taxing on patients due to several issues related to the very nature of dementia, such as difficulty in understanding instructions, lapse in attention and motivation. For that reason, researchers are now turning their attention to studying how the brain controls the movements of the eye for clues on the human brain’s cognitive abilities such as attention and memory.

“This study takes this work forward because we found strong evidence that the difficulty in noticing and correcting the errors was probably caused by a problem in the memory networks of the brain that allow us to store the spatial position of objects in the environment,” said Dr Trevor Crawford, who works at the department of Psychology and the Centre for Aging Research at Lancaster University.

According to the Fisher Center for Alzheimer’s Research Foundation, 35 million in the world suffer from Alzheimer’s, and 5.3 million of those people are in the United States. It is the fifth leading cause of death in people who are 65 or older. Symptoms can take years to appear so diagnosing the process as early as possible is crucial for better management of the disease.

Details of the research were published in Journal of the American Aging Association.