Now, a simple eye test to detect Alzheimer's early

A simple eye test could diagnose Alzheimer's years before any tell-tale symptoms appear as scientists have discovered a link between cataract and the degenerative brain disease.

The finding, by researchers at Boston University Schools of Medicine, indicates that dementia might originate outside the brain and be connected to the body as a whole. A growing amount of evidence suggests cataracts and Alzheimer's - both associated with increasing age - may share common factors, the 'Daily Mail' reported.

Scientists say the finding will pave way for new treatments for the brain disease and a simple eye test which can detect Alzheimer's disease. The discovery means diagnosing Alzheimer's could be done earlier and suggests new treatment targets for the debilitating disease.

After looking at brain MRI scans a decade after an original eye exam, researchers found another link between cortical cataract formation and poorer results on cognitive tests given to patients. They then performed a genome-wide association study on nearly 190,000 DNA sequence variations, focusing on a protein called delta-catenin.

The protein has previously been implicated in brain and eye development, but not directly in either cataracts or Alzheimer's. The study also revealed increased deposits of delta-catenin in lens tissue of autopsy-confirmed Alzheimer's cases. "This study gives hope that we are moving toward earlier diagnosis and new treatment targets for this debilitating disease," said Professor Lindsay Farrer. The research is published in the journal 'PLoS ONE'.