There is an old saying that “the eyes are the windows to the soul.” In other words, we can interpret what someone is thinking and feeling by analyzing the expression in their eyes. Psychology studies have shown that certain expressions bely the true feelings of a person. A tangible example would be dilated pupils indicating excitement, but there are many other nonverbal clues one gets when looking at someone’s eyes. They elongate and shine when happy, constrict when suspicious. While we can often hide our facial expression, we cannot stop our eyes from reflecting how we truly feel.
Alzheimer disease is a progressive, neurodegenerative disease characterized by deterioration in memory and other neurocognitive functions. It is the most common form of dementia. I watched my grandfather, a brilliant man who was the fifth president of Sanwa Bank when it was the most profitable bank in the world, become ravaged by Alzheimer disease. He guided the bank in the postwar era, financing many major Japanese companies, including Toyota. He founded the Japan Credit Bureau, which was the pioneer of the Japanese credit card business. His financial brilliance could not fight the disease that robbed him of all his recollections and left him a shell of a man at his passing.
Our understanding of the disease has increased immensely over the years and therapeutics to slow cognitive decline are available and more are being developed. The predominant hypothesis for its pathogenesis is that misfolded amyloid-𝛽 oligomers and tau protein neurofibrillary tangles induce oxidative stress and inflammatory damage to the brain. Sound familiar? The parallels between age-related macular degeneration and Alzheimer disease are frightening.
Retinal changes, including reduced retinal nerve fiber and ganglion cell layer thickness, amyloid-𝛽 accumulation in the retina, and changes in retinal vasculature have all correlated with cognitive decline. In this issue, we look closely at the retinal biomarkers of Alzheimer disease. In many of the Alzheimer therapeutic studies, optical coherence tomography (OCT) and OCT angiography are becoming common tools to evaluate for drug effects.
I remember my last meeting with my beloved grandfather in Japan. His mind was no longer with him, but I am comforted by the fact that his eyes seemed to reflect his love and understanding that we were there to say goodbye. RP