Abstract
We have been developing a new diagnostic method for Alzheimer's disease utilizing miotic reflex to light. In our previous studies, we found that a miotic ratio and miotic time were significantly smaller and longer, respectively, in Alzheimer's disease and cerebrovascular dementia patients than those in normal aged persons when pupils were exposed to visible light. In this study, we improved our measurement system so that we could measure miotic reflex quantitatively and in real time. We developed a glasses-type measurement device that consisted of visible and infrared light emitting diodes and an infrared CCD camera. In this system, a flashlight was for light stimulation and miotic reflex curves were obtained automatically and in real time. We also examined the usefulness of several parameters for diagnosis and found that delay time, miotic ratio, recovery time and recovery velocity of patients significantly differed from those of normal subjects, suggesting that these parameters might be effective for the diagnosis.
