an image processing technique for diagnosis of alzheimer's disease

background : patients with alzheimer's disease (ad) reportedly hibit hypersensitivity to much diluted tropicam solution (0.005%), a m4 muscarinic receptor antagonist. therefore aocular application of 0.005% tropicamide ma be useful for screening dementia. the aim of this study was to simplify the pupil response test by using a new image analyzing system, which consists of a cheap, simple, and easy to use web-camera and a computer. methods : intraocular tropicamide of 0.005% concentration was administered in 3 groups: alzheimer's disease patients (n = 8, average age = 76 ± 5), non-alzheimer's disease elderly (n = 6, average age = 65 ± 7), and young subjects (n = 8, average age = 28 ± 5). every 5 minutes for 60 minutes, image of the eye's shape were taken, and the diameter of the pupils was measured. results : the results showed that differences in pupil dilation rate between alzheimer's disease and non-alzheimer's disease subjects were statistically significant. roc analysis showed that after 35 minutes the sensitivity and specificity of the test were 100%. conclusions : based on our results, we concluded that this recording system might be an appropriate and reliable tool for pupil response diagnosis test of alzheimer's disease. keywords : alzheimer’s disease, tropicamide, pupil.