According to a new study by scientists at the University College London, retinal cells may be able to offer an early peek at Alzheimer's disease. Since the retina is a direct extension of the brain these scientists believe that by visualizing dying cells in the retina they may be able to extrapolate what's going on in terms of cell death within the brain. It is an interesting idea, although I'm curious to see what happens once human trials start later this year. Since Alzheimer's doesn't affect the same area of the brain in every individual I wonder how accurate it will be. Also, what about people with conditions like macular degeneration, a common eye disease causing retinal cell death in individuals over 50? If the dyes in this new test for Alzheimer's target dead and dying cells in the retina, couldn't this lead to false positives especially since many older people who would be at risk of Alzheimer's also tend to have retinal degeneration as a result of their age?